Battery cell, battery device and power-consuming device

Abstract

Battery cell comprising: a housing body, an electrode assembly and an electrolyte, wherein the electrode assembly 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 film layer, wherein the positive electrode current collector comprises a positive electrode main body section and a positive electrode tab section, wherein the positive electrode tab section extends from the positive electrode main body section, wherein the positive electrode film layer is located on at least one side of the positive electrode main body section, wherein the positive electrode film layer comprises a lithium-containing phosphate, and wherein the positive electrode film layer has a size of 200 mm to 700 mm along a longitudinal direction of the positive electrode sheet; wherein the negative electrode sheet comprises a negative electrode current collector and a negative electrode film layer, wherein the negative electrode current collector comprises a negative electrode main body section and a negative electrode tab section, wherein the negative electrode tab section extends from the negative electrode main body section, wherein the negative electrode film layer is located on at least one side of the positive electrode main body section, and wherein the negative electrode film layer comprises graphite; wherein the electrolyte comprises a chain-like carboxylate, wherein a mass fraction of the chain-like carboxylate relative to a total mass of the electrolyte is 5% to 60%.

Description

Technical field

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

[0002] Batteries are not only used in energy storage and power supply systems such as hydroelectric, thermal, wind, and solar power plants, but also find widespread application in electric transport vehicles such as e-bikes, e-motorcycles, and electric cars, as well as in military equipment, aerospace, and other sectors. Current battery cells cannot simultaneously meet the requirements for fast charging capability and high energy density. Content of the present invention

[0003] The first aspect of the present application provides a battery cell comprising a casing, an electrode arrangement, and an electrolyte, wherein the electrode arrangement comprises a positive electrode sheet, a negative electrode sheet, and a separator arranged 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 film layer, wherein the positive electrode current collector comprises a positive electrode main body section and a positive electrode tab section, the positive electrode tab section extending from the positive electrode main body section, wherein the positive electrode film layer is located on at least one side of the positive electrode main body section, and wherein the positive electrode film layer comprises a lithium-containing phosphate.wherein the positive electrode film layer has a size of 200 mm to 700 mm along a longitudinal direction of the positive electrode sheet; wherein the negative electrode sheet comprises a negative electrode current collector and a negative electrode film layer, wherein the negative electrode current collector comprises a negative electrode main body and a negative electrode tab section, the negative electrode tab section extending from the negative electrode main body section, wherein the negative electrode film layer is located on at least one side of the positive electrode main body section, and wherein the negative electrode film layer comprises graphite; wherein the electrolyte comprises a chain-like carboxylate,and wherein the mass fraction of the chain-like carboxylate, relative to the total mass of the electrolyte, is 5% to 60%. Therefore, increasing the size of the positive electrode film layer increases the energy density of the battery cell, and simultaneously, through combination with the aforementioned content of chain-like carboxylate, increases the conductivity of the electrolyte and improves the fast-charging performance of the battery cell, resulting in a battery cell with both relatively high energy density and excellent fast-charging performance.

[0004] According to some embodiments of the present application, the size of the positive electrode film layer along the longitudinal direction of the positive electrode sheet is 400 mm to 650 mm. This further increases the energy density of the battery cell.

[0005] According to some embodiments of the present application, the mass fraction of the chain-like carboxylate, based on the total mass of the electrolyte, is 8% to 30%. This improves the conductivity of the electrolyte and simultaneously reduces the risk of gas formation in the battery cell under high-temperature conditions, resulting in a battery cell with both excellent fast-charging performance and cycle life at high temperatures.

[0006] According to some embodiments of the present application, the conductivity of the electrolyte at room temperature is 9.5 mS / cm to 19 mS / cm. This improves the fast charging performance of the battery cell.

[0007] According to some embodiments of the present application, the conductivity of the electrolyte at room temperature is 9.7 mS / cm to 13.5 mS / cm. This reduces the risk of electrolyte gas formation and simultaneously increases the migration rate of lithium ions.

[0008] According to some embodiments of the present application, the viscosity of the electrolyte at room temperature is 2 mPa·s to 5 mPa·s. This increases the migration rate of the lithium ions and reduces the internal resistance of the battery cell.

[0009] According to some embodiments of the present application, the density of the electrolyte at room temperature is 1.05 g / mL to 1.35 g / mL. This increases the migration rate of lithium ions in the electrolyte and reduces the internal resistance of the battery cell.

[0010] According to some embodiments of the present application, the chain-like carboxylate comprises a compound represented by formula I: where R1 comprises one or more of the following substances: a hydrogen atom, a C1- R2 comprises one or more of the following: a C1-C5 alkyl group and a C1-C5 haloalkyl group. Therefore, the aforementioned type of chain-like carboxylate has a low molecular weight, which can improve the conductivity of the electrolyte. Combined with a long electrode sheet, this can result in a battery cell with relatively high energy density, excellent fast-charging performance, and excellent cycle life at high temperatures.

[0011] According to some embodiments of the present application, R1 comprises one or more of the following: a hydrogen atom, a C1-C3 alkyl group, and a C1-C3 haloalkyl group; and / or R2 comprises one or more of the following: a C1-C3 alkyl group and a C1-C3 haloalkyl group. This increases the conductivity of the electrolyte.

[0012] According to some embodiments of the present application, the chain-like carboxylate comprises one or more of the following formulas: Therefore, the above-mentioned type of chain-like carboxylate has a low molecular weight, which can improve the conductivity of the electrolyte.

[0013] According to some embodiments of the present application, a one-sided coating weight of the positive electrode film layer is 200 mg / 1540.25 mm². 2 up to 340 mg / 1540.25 mm 2 , optional 240 mg / 1540.25 mm 2 up to 300 mg / 1540.25 mm2 This increases the energy density of the battery cell.

[0014] According to some embodiments of the present application, the compaction density of the positive electrode film layer is 2.5 g / cm³. 3 up to 2.8 g / cm³ 3 This occurs when the battery cell is at 100% state of charge (SOC). This increases the energy density of the battery cell.

[0015] According to some embodiments of the present application, the lithium-containing phosphate comprises at least one of the following materials: a lithium iron phosphate material and a lithium manganese iron phosphate material. This improves the safety performance and cycle life of the battery cell.

[0016] According to some embodiments of the present application, the positive electrode film layer further comprises a lithium supplement, wherein the mass fraction of the lithium supplement is 0.5% to 2.5% relative to the total mass of the positive electrode film layer. This compensates for the loss of active lithium during the formation phase and improves the energy density and cycle life of the individual battery cell.

[0017] According to some embodiments of the present application, the lithium supplement comprises one or more of the following substances: lithium nickel cobalt manganese oxide, lithium phosphate, lithium hydrogen phosphate, lithium sulfate, lithium sulfite, lithium molybdate, lithium oxalate, lithium titanate, lithium tetraborate, lithium metasilicate, lithium metamanganate, lithium tartrate, trilithium citrate, lithium nickel oxide and lithium ferrite.

[0018] According to some embodiments of the present application, the positive electrode sheet and the negative electrode sheet are stacked on top of each other. This improves space utilization within the battery cell and increases the energy density of the battery cell.

[0019] According to some embodiments of the present application, the battery cell comprises a housing body, a first end cover arrangement and a second end cover arrangement, wherein the housing body, the first end cover arrangement and the second end cover arrangement define a receiving cavity, wherein the first end cover arrangement comprises a first end cover and at least one positive electrode terminal, wherein the positive electrode main body section is electrically connected to the positive electrode terminal via the positive electrode tab section; and / or wherein the second end cover arrangement comprises a second end cover and at least one negative electrode terminal, wherein the negative electrode main body section is electrically connected to the negative electrode terminal via the negative electrode tab section.This reduces the risk of short circuits between the positive and negative electrodes and improves the safety of the battery cell.

[0020] According to some embodiments of the present application, the first end cap arrangement comprises one positive electrode terminal and one negative electrode terminal, wherein the positive electrode body section is electrically connected to the positive electrode terminal via the positive electrode tab section and the negative electrode body section is electrically connected to the negative electrode terminal via the negative electrode tab section; and / or wherein the second end cap arrangement comprises one positive electrode terminal and one negative electrode terminal, wherein the positive electrode body section is electrically connected to the positive electrode terminal via the positive electrode tab section and the negative electrode body section is electrically connected to the negative electrode terminal via the negative electrode tab section.This improves the current-carrying capacity of the battery cell.

[0021] According to some embodiments of the present application, the first end cap arrangement and the second end cap arrangement are arranged at both ends of the housing body, wherein the electrode terminals with the same polarities are arranged offset along the longitudinal direction of the battery cell on the first end cap arrangement and on the second end cap arrangement, and optionally, the electrode terminals with the same polarities are arranged diagonally along the longitudinal direction of the battery cell. This reduces the temperature rise of the battery cell during charging and thus reduces the impedance of the battery cell.

[0022] According to some embodiments of the present application, the battery cell is configured to charge from 10% SOC to 80% SOC in a charging time of 5 to 10.5 minutes. This improves the fast-charging performance of the battery cell.

[0023] A second aspect of the present application relates to a battery device comprising the battery cell provided by the first aspect of the present application, wherein the battery device is at least one of the following: battery module, battery pack and energy storage device.

[0024] The third aspect of the present application provides a power-consuming device comprising the battery cell provided by the first aspect of the present application or the battery device provided by the second aspect of the present application, wherein the battery cell or the battery device is used to provide electrical energy.

[0025] The additional aspects and advantages of the present application are partly specified in the following description, and partly become apparent from the following description or are understandable through the practical application of the present application. Brief description of the drawing

[0026] Several additional advantages and benefits will become clear to the person skilled in the art upon reading the following detailed description of the preferred embodiments. The drawings serve only to illustrate the preferred embodiments and are not to be regarded as limiting the present application. Furthermore, the same reference numerals are used in all drawings to denote the same parts. They show: Fig. 1 a schematic diagram of a positive electrode sheet according to an embodiment of the present application; Fig. 2 a schematic diagram of a stacking method of an electrode arrangement according to an embodiment of the present application; Fig. 3 a schematic structure diagram of a housing body according to an embodiment of the present application; Fig.4 a schematic diagram of a first end cover arrangement according to an embodiment of the present application; Fig. 5 an exploded view of the first end cap assembly Fig. 4; Fig. 6 a schematic structure diagram of the first end cover arrangement Fig. 4 from a different perspective; Fig. 7 a cross-sectional view of the first end cover arrangement Fig. 6 along AA' direction; Fig. 8 a schematic diagram of a second end cover arrangement according to an embodiment of the present application; Fig. 9 an exploded view of the second end cover assembly Fig. 8; Fig. 10 a schematic structure diagram of the second end cover arrangement Fig. 8 from a different perspective; Fig. 11 a cross-sectional view of the second end cover arrangement Fig. 10 along BB' direction; Fig. 12 a schematic structure diagram of a battery cell according to an embodiment of the present application; Fig. 13 a schematic structure diagram of a first end cover arrangement according to an embodiment of the present application; Fig. 14 an exploded view of the first end cover assembly from Fig. 13; Fig. 15 a schematic structure diagram of the first end cover arrangement Fig. 13 from a different perspective; Fig. 16 a cross-sectional view of the first end cover arrangement Fig. 15 along CC' direction; Fig. 17 a schematic structure diagram of a second end cover arrangement according to an embodiment of the present application; Fig. 18 an exploded view of the second end cover assembly from Fig. 17; Fig.19 a schematic structure diagram of the second end cover arrangement Fig. 17 from a different perspective; Fig. 20 a cross-sectional view of the second end cover arrangement from Fig. 19 along DD' direction; Fig. 21 a schematic structure diagram of an electrode arrangement according to an embodiment of the present application; Fig. 22 a schematic structure diagram of an electrode arrangement according to another embodiment of the present application; Fig. 23 a schematic diagram of a power-consuming device according to an embodiment of the present application. Explanation of reference symbols:

[0027] 1 Battery cell; 11 Housing body; 12 First end cap assembly; 13 Second opening; 121 First end cap; 1211 First through hole; 1212 Liquid injection hole; 122 Positive electrode terminal; 123 First insulating element; 1231 First opening; 124 First sealing element; 125 First positioning element; 126 Second insulating element; 127 Rivet block; 131 Second end cap; 1311 Third opening; 132 Negative electrode terminal; 133 Third insulating element; 1331 Fourth opening; 134 Second sealing element; 135 Second positioning element; 136 Fourth insulating element; 137 Pressure relief mechanism; 2 Positive electrode sheet; 21 Positive electrode current collector; 211 Positive main body section; 212 Positive electrode tab section; 2121 First positive electrode tab; 2122 Second positive electrode tab; 22 Positive electrode film layer; 3 Negative electrode sheet; 31 First negative electrode tab; 32 Second negative electrode tab; 4 Separator; 20 Electrode arrangement. Detailed descriptions

[0028] The following are detailed descriptions of the embodiments of the technical solution of the present application. These embodiments serve only to clarify the technical solution of the present application and are therefore merely examples; they cannot be used to limit the scope of protection of the present application.

[0029] The reference to "embodiment" here means that a particular feature, structure, or property described in connection with the embodiments may be included in at least one embodiment of the present application. The occurrence of this expression at different points in the description does not necessarily always refer to the same embodiment, nor is it an independent or alternative embodiment that excludes other embodiments. It is expressly and implicitly clear to the person skilled in the art that the embodiments described herein may be combined with other embodiments.

[0030] Unless otherwise stated, all embodiments and optional embodiments of the present application may be combined to form a new technical solution.

[0031] Unless otherwise stated, all technical features and optional technical features of the present application may be combined to form a new technical solution.

[0032] Unless otherwise stated, all steps of the present application may be carried out successively or in any order, but preferably consecutively. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) carried out consecutively, or that the method may include steps (b) and (a) carried out consecutively. For example, this means that the method may also include step (c), that step (c) may be added in any order, and the method may, for example, include steps (a), (b) and (c), or steps (a), (c) and (b), or steps (c), (a) and (b), etc.

[0033] According to market developments, batteries are being used more and more frequently. Batteries are not only used in energy storage and power supply systems such as hydroelectric, thermal, wind, and solar power plants, but also find widespread application in electric transport vehicles such as e-bikes, e-motorcycles, and electric cars, as well as in military equipment, aerospace, and other sectors. As the applications of batteries continue to expand, market demand is also constantly increasing. Current battery technology cannot simultaneously meet the requirements regarding specific energy, fast charging capability, and long cycle life.

[0034] The battery cell proposed in this application increases its energy density by extending the coating length of the positive electrode film layer on the positive electrode sheet. This increases the charging capacity of the lithium-containing phosphate and thus the energy density of the battery cell. However, with increasing size of the positive electrode film layer, the electron conduction path lengthens, which limits the fast-charging capability of the battery cell. By further increasing the content of chain-like carboxylate in the electrolyte, the electrolyte can fully infiltrate the positive electrode film layer even with a relatively long electrode sheet. This significantly increases the electron and ion conductivity of the positive electrode film layer and also improves the transfer capacity of lithium ions in the liquid phase, thus significantly improving the fast-charging performance of the relatively long battery cell.However, increasing the content of chain-like carboxylate also intensifies side reactions in the battery and leads to electrolyte gas formation, which can easily increase the concentration of acidic substances in the electrolyte. This, in turn, can lead to corrosion of the electrolyte interface film (SEI film) and impair the battery's lifespan at high temperatures. This application determines the appropriate content of chain-like carboxylate, suitable for battery cells with a positive electrode film layer size of 200 mm to 700 mm, by comprehensively regulating the electrode sheet length and solvent composition, so that the battery cell exhibits both good fast-charging capability and a good cycle life at high temperatures.

[0035] The battery cell provided for in the present application can be used in power-consuming devices that utilize the battery cell as a power source, or in various energy storage systems that use the battery cell as an energy storage element. Power-consuming devices include, among others, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, ships, spacecraft, etc. Electric toys include, among others, stationary or mobile electric toys such as game consoles, electric toy cars, electric toy ships, and electric toy airplanes, etc. Spacecraft include, among others, airplanes, rockets, space shuttles, and spacecraft.

[0036] In a first aspect of the present application, a battery cell is provided comprising a housing body, an electrode arrangement and an electrolyte, wherein the electrode arrangement comprises a positive electrode sheet, a negative electrode sheet and a separator between the positive and the negative electrode sheet.

[0037] Referring to Fig.1 The positive electrode sheet 2 comprises a positive electrode current collector 21 and a positive electrode film layer 22, wherein the positive electrode current collector 21 comprises a positive electrode main body section 211 and a positive electrode tab section 212, wherein the positive electrode tab section 212 extends from the positive electrode main body section 211, wherein the positive electrode film layer 22 is located on at least one side of the positive electrode main body section 211, wherein the positive electrode film layer comprises a positive electrode active material, wherein the positive electrode active material comprises a lithium-containing phosphate, and wherein the positive electrode film layer 22 has a size of 200 mm to 700 mm along a longitudinal direction of the positive electrode sheet 2.

[0038] The negative electrode sheet comprises a negative electrode current collector and a negative electrode film layer, wherein the negative electrode current collector comprises a negative electrode main body section and a negative electrode tab section, wherein the negative electrode tab section extends from the negative electrode main body section, wherein the negative electrode film layer is located on at least one side of the positive electrode main body section, and wherein the negative electrode film layer comprises a negative electrode active material, the negative electrode active material comprising graphite.

[0039] The electrolyte comprises a chain-like carboxylate, with the mass fraction of the chain-like carboxylate being between 5% and 60% of the total mass of the electrolyte.

[0040] Therefore, the battery cell proposed in the present application has a relatively long coating length of the positive electrode film layer, which increases the charging capacity of the lithium-containing phosphate on the positive electrode sheet, thereby resulting in a battery cell with a higher energy density, whereby the conductivity of the electrolyte can be increased by adding 5% to 60% chain-like carboxylate, thereby increasing the conductivity of the electrode sheet with a relatively long positive electrode film layer and thus improving the fast charging performance of the battery cell.

[0041] In this application, the size of the positive electrode film layer refers to the size of the positive electrode film layer on at least one side of the positive electrode main body section in the longitudinal direction of the positive electrode current collector, see L in Fig.1, this is the size of the positive electrode film layer.

[0042] For example, the size L of the positive electrode film layer can be 200 mm, 300 mm, 350 mm, 400 mm, 450 mm, 500 mm, 550 mm, 600 mm, 650 mm, 700 mm, etc., or a range consisting of any of the above values. This increases the content of lithium phosphates on the positive electrode sheet and results in a battery cell with good safety performance, good cycle life, and high energy density.

[0043] According to some specific embodiments of the present application, the size L of the positive electrode film layer along the direction in which the positive electrode tab section extends from the positive electrode main body section is 400 mm to 650 mm. This increases the volume energy density of the battery cell while reducing the electron conduction path, thereby improving the fast-charging performance of the battery cell.

[0044] According to some embodiments of the present application, the conductivity of the electrolyte at room temperature is 9.5 mS / cm to 19 mS / cm.

[0045] For example, the conductivity of the electrolyte can be 9.5 mS / cm, 10 mS / cm, 12 mS / cm, 14 mS / cm, 16 mS / cm, 18 mS / cm, 19 mS / cm, etc., or a range consisting of any of the above values. This improves the rate performance of the battery cell.

[0046] According to some embodiments of the present application, the conductivity of the electrolyte at room temperature is 9.7 mS / cm to 13.5 mS / cm. This improves the fast-charging performance of the battery cell and reduces the risk of gas formation in the battery cell under high-temperature conditions, thereby improving the cycle performance of the battery cell at high temperatures.

[0047] In the present application, a conductivity meter is used after disassembly of the battery cell to obtain the electrolyte, whereby the conductivity of the electrolyte at room temperature can be checked with reference to HG-T 4067-2015.

[0048] According to some embodiments of the present application, the mass fraction of the chain-like carboxylate, based on the total mass of the electrolyte, can be 5% to 60%, for example, 5%, 10%, 20%, 30%, 40%, 50%, 60%, etc., or lie within a range consisting of any of the aforementioned values. By maintaining the content of the chain-like carboxylate within the aforementioned range, the viscosity of the electrolyte can be reduced, the internal resistance of the battery cell reduced, the migration rate of lithium ions increased, and the fast-charging performance of the battery cell improved; on the other hand, the risk of electrolyte gas formation under high-temperature conditions can be reduced, and the cycle life of the battery cell under high temperatures increased, thus obtaining a battery cell with high energy density, excellent fast-charging performance, and cycle life under high temperatures.

[0049] According to some specific embodiments of the present application, the mass fraction of the chain-like carboxylate, relative to the total mass of the electrolyte, can be 8% to 30%. This improves the fast-charging performance of the battery cell and reduces the risk of gas formation in the battery cell under high-temperature conditions, thereby improving the battery's cycle life at high temperatures.

[0050] In the present application, after disassembly of the battery cell to obtain the electrolyte, the qualitative and quantitative detection of the chain-like carboxylate can be carried out using gas chromatography-ion chromatography (GC-IC).

[0051] According to some embodiments of the present application, the viscosity of the electrolyte at room temperature can be between 2 mPa·s and 5 mPa·s. For example, it can be 2 mPa·s, 2.5 mPa·s, 3 mPa·s, 3.5 mPa·s, 4 mPa·s, 4.5 mPa·s, 5 mPa·s, etc., or a range consisting of any of the aforementioned values. This results in a relatively low viscosity of the electrolyte, which increases the migration rate of lithium ions, reduces the internal resistance of the battery cell, and improves the fast-charging performance of the battery cell.

[0052] In the present application, after disassembling the battery cell to obtain the electrolyte, a motion viscometer is used to check the viscosity of the electrolyte, whereby the viscosity of the electrolyte at room temperature can be checked with reference to GB / T 10247-2008.

[0053] According to some embodiments of the present application, the density of the electrolyte at room temperature can range from 1.05 g / mL to 1.35 g / mL. For example, it can be 1.05 g / mL, 1.1 g / mL, 1.15 g / mL, 1.2 g / mL, 1.25 g / mL, 1.3 g / mL, 1.35 g / mL, etc., or a range consisting of any of the aforementioned values. This reduces the viscosity of the electrolyte, which increases the migration rate of lithium ions in the electrolyte, reduces the internal resistance of the battery cell, and improves the fast-charging performance of the battery cell.

[0054] In the present application, after disassembling the battery cell to recover the electrolyte, a liquid density meter is used to check the density of the electrolyte, whereby the density of the electrolyte can be checked at room temperature with reference to GB / T 2013-2010.

[0055] According to some embodiments of the present application, the chain-like carboxylate may comprise a compound represented by formula I: wherein R1 comprises one or more of the following: a hydrogen atom, a C1-C5 alkyl group and a C1-C5 haloalkyl group, while R2 comprises one or more of the following: a C1-C5 alkyl group and a C1-C5 haloalkyl group.

[0056] If the mass fraction of the chain-like carboxylate specified in Formula I is 5% to 60%, the use of the chain-like carboxylate of the type and quantity mentioned above improves, on the one hand, the wettability of the electrolyte in the electrode film layer, especially in longer battery cells, the uniformity of electrolyte wetting in the longitudinal direction of the electrode sheet, the electron permeability of the active material, and also the lithium ion migration rate in the electrolyte, thereby improving the fast charging performance of the battery cell. On the other hand, an excessively high content of chain-like carboxylate also increases gas formation in the battery cell, which impairs battery circulation at high temperatures. This means that an appropriate amount of chain-like carboxylate can also reduce the risk of electrolyte gas formation at high temperatures and extend the battery's service life at high temperatures.

[0057] According to some embodiments of the present application, R1 comprises one or more of the following substances: a hydrogen atom, a C1-C3 alkyl group, and a C1-C3 haloalkyl group. For example, R1 may comprise one or more of the following substances: a hydrogen atom, a methyl group, an ethyl group, a propyl group, a fluoromethyl group, a fluoroethyl group, and a fluoropropyl group. This increases the conductivity of the electrolyte.

[0058] According to some embodiments of the present application, R2 comprises one or more of the following substances: a C1-C3 alkyl group and a C1-C3 haloalkyl group. For example, R2 can be one or more of the following substances: a methyl group, an ethyl group, a propyl group, a fluoromethyl group, a fluoroethyl group, and a fluoropropyl group. This increases the conductivity of the electrolyte.

[0059] According to some embodiments of the present application, the chain-like carboxylate can comprise one or more of the following formulas: Formula I-8. Therefore, the above-mentioned type of chain-like carboxylate has a low molecular weight, which can improve the conductivity of the electrolyte.

[0060] According to some embodiments of the present application, the one-sided coating weight of the positive electrode film layer can be 200 mg / 1540.25 mm². 2 up to - 340 mg / 1540.25 mm 2 It can be, for example, 200 mg / 1540.25 mm 2 , 230 mg / 1540.25 mm 2 , 260 mg / 1540.25 mm 2 , 290 mg / 1540.25 mm 2 , 320 mg / 1540.25 mm 2 , 340 mg / 1540.25 mm 2etc., or be a range consisting of any of the values ​​mentioned above. Therefore, the energy density of the battery cell can be increased by setting the size of the positive electrode film layer to between 200 mm and 700 mm and by setting the coating weight of the positive electrode film layer to the range mentioned above.

[0061] In some embodiments, the electrolyte salt may comprise at least one of the following substances: lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bistrifluoromethanesulfonylimide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium bisoxalatoborate, lithium difluorodioxalatophosphate and lithium tetrafluorooxalatophosphate.

[0062] In some embodiments, the electrolyte may optionally include an additive. For example, the additive may include an additive for film formation of the negative electrode, an additive for film formation of the positive electrode, and an additive for improving certain battery properties, such as an additive to improve the battery's overcharge resistance, an additive to improve high-temperature performance, or a low-temperature performance.

[0063] According to some specific embodiments of the present application, the one-sided coating weight of the positive electrode film layer can be 240 mg / 1540.25 mm². 2 up to 300 mg / 1540.25 mm 2 For example, it could be 240 mg / 1540.25 mm 2 , 260 mg / 1540.25 mm 2 , 280 mg / 1540.25 mm 2 , 300 mg / 1540.25 mm 2etc., or be a range consisting of any of the values ​​mentioned above. This increases the energy density of the battery cell.

[0064] The present application provides a method for testing the coating weight of the positive electrode film layer: Disassembling a battery cell to obtain a positive electrode sheet, for example, taking a single-sided coated positive electrode sheet (if it is a double-sided coated electrode sheet, the positive electrode film layer on one side can be wiped off first) and punching it into a small disc with an area of ​​S1, weighing it and recording it as M1. Then, the positive electrode film layer of the weighed positive electrode sheet is wiped off, and the weight of the positive electrode current collector is weighed and recorded as M0. The single-sided coating weight of the positive electrode film layer = (M1 - M0) / S1.

[0065] According to some embodiments of the present application, the compaction density of the positive electrode film layer can be 2.5 g / cm³. 3 up to 2.8 g / cm³ 3 This is the value when the battery cell is at 100% state of charge (SOC). For example, it can be 2.5 g / cm³. 3 , 2.55 g / cm³ 3 , 2.6 g / cm³ 3 , 2.65 g / cm³ 3 , 2.7 g / cm³ 3 , 2.75 g / cm³ 3 , 2.8 g / cm³ 3etc., or be a range consisting of any of the values ​​mentioned above. Therefore, if the compaction density of the positive electrode film layer is within the range mentioned above, the stacking of the positive electrode sheets is relatively dense, which has a positive effect on improving the energy density of the battery cell. Furthermore, the contact resistance between the particles is relatively low, which can further reduce the internal resistance of the battery cell, reduce heat generation from the battery cell, and improve the high-temperature performance of the battery cell.

[0066] The present application provides a method for testing the compaction density of the positive electrode film layer: charging to 3.8 V with a constant current of 1 / 3 C and charging to 0.05 C with a constant voltage of 3.8 V, disassembling a battery cell to obtain a positive electrode sheet, for example, taking a single-sided coated positive electrode sheet (if it is a double-sided coated electrode sheet, the positive electrode film layer on one side can be wiped off first) and punching it into a small disc with an area of ​​S1, weighing and recording as M1 and measuring its thickness H1. Then the positive electrode film layer of the weighed positive electrode sheet is wiped off, the weight of the positive electrode current collector being weighed and recorded as M0, and its thickness being measured as H0.The one-sided coating weight of the positive electrode film layer = (M1 - M0) / S1, the thickness of the positive electrode film layer = H1 - H0 and the compaction density of the positive electrode film layer = the one-sided coating weight of the positive electrode film layer / the thickness of the positive electrode film layer.

[0067] According to some embodiments of the present application, the lithium-containing phosphate comprises at least one of the following substances: a lithium iron phosphate material and a lithium manganese iron phosphate material. This improves the cycle performance of the battery cell.

[0068] According to some embodiments of the present application, the lithium-containing phosphate comprises a compound represented by formula 11: Li x1 A y1 Me a M b P 1-c X c Y z Formula II where 0.5≤x1≤1.3, 0≤y1≤1.3 and 0.9≤x1+y1≤1.3, 0.9≤a<1.5, 0 <b≤0,5 und 0,9≤a+b≤1,5, 0≤c≤0,5, 3≤z≤5, wobei A eines oder mehrere der folgenden Elemente umfasst: Na, K und Mg, wobei Me eines oder mehrere der folgenden Elemente umfasst: Mn, Fe, Co und Ni, wobei M eines oder mehrere der folgenden Elemente umfasst: B, Mg, Al, P, Ca, Sc, Ti, V, Cr, Cu, Zn, Sr, Y, Zr, Nb, Mo, Cd, Sn, Sb, Te, Ba, Ta, W, Yb, La und Ce, wobei X ein oder mehrere der folgenden Elemente umfasst: S, Si, Cl, B, C und N, und wobei Y ein oder zwei der folgenden Elemente umfasst: 0 und F.

[0069] According to some embodiments of the present application, the positive electrode film layer further comprises a lithium supplement, wherein the mass fraction of the lithium supplement, based on the total mass of the positive electrode film layer, can be from 0.5% to 2.5%. For example, it can be 0.5%, 0.7%, 1%, 1.3%, 1.6%, 1.85%, 2.2%, 2.5%, etc., or a range consisting of any of the aforementioned values. In this way, lithium ions can be replenished for the positive electrode film layer to compensate for lithium ion loss, thereby increasing the capacity of the battery cell and improving its energy density and cycle life.

[0070] According to some embodiments of the present application, the lithium additive can comprise one or more of the following substances: lithium nickel cobalt manganese oxide, lithium phosphate, lithium hydrogen phosphate, lithium sulfate, lithium sulfite, lithium molybdate, lithium oxalate, lithium titanate, lithium tetraborate, lithium metasilicate, lithium metamanganate, lithium tartrate, trilithium citrate, lithium nickel oxide, and lithium ferrite. This increases the energy density of the battery cell.

[0071] According to some specific embodiments of the present application, the lithium supplement comprises a lithium ferrite, wherein during the battery cycle the lithium ferrite can release oxygen radicals which are involved in the film formation of the negative electrode, further reducing the internal resistance of the battery cell and improving the fast charging performance of the battery cell.

[0072] According to some embodiments of the present application, with reference to Fig. In the battery cell, the positive electrode sheet 2 and the negative electrode sheet 3 are stacked on top of each other. Specifically, a separator 4 is provided between the positive electrode sheet 2 and the negative electrode sheet 3 to prevent a short circuit between them. This improves space utilization within the battery cell and increases the energy density of the battery cell.

[0073] In some embodiments, the positive electrode current collector can utilize 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 base layer and a metal layer formed on at least one surface of the polymer base layer. The composite current collector can be formed by depositing a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, silver alloy, etc.) onto a polymer substrate (such as polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0074] In some embodiments, the positive electrode film layer may optionally further comprise a binder. For example, the binder may comprise at least one of the following substances: polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorine-containing acrylate resin.

[0075] In some embodiments, the positive electrode film layer may optionally further comprise a conductive medium. For example, the conductive medium may comprise at least one of the following materials: superconducting carbon, acetylene carbon black, carbon black, ketone black, a carbon dot, a carbon nanotube, graphene, and a carbon nanofiber.

[0076] In some embodiments, the positive electrode sheet can be produced in the following manner: the above-mentioned components for producing the positive electrode sheet, such as the positive electrode active material, the conductive agent, the binder and any other components, are dispersed in a solvent (such as N-methylpyrrolidone) to form a positive electrode paste, which is applied to the positive electrode current collector, whereby after drying, cold pressing and other processes the positive electrode sheet can be obtained.

[0077] In some embodiments, the negative electrode current collector can use 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 substrate and a metal layer formed on at least one surface of the polymer base layer. 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 a polymer material substrate (such as polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0078] 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 of the following materials: synthetic graphite, natural graphite, soft carbon, hard carbon, a silicon-based material, a tin-based material, a titanate, and the like. The silicon-based material can be selected from at least one of the following: elemental silicon, a silicon-oxygen compound, a silicon-carbon composite, a silicon-nitrogen composite, and a silicon alloy. The tin-based material can be selected from at least one of the following: elemental tin, a tin oxide compound, and a tin alloy.If the battery is a lithium-ion battery, the titanate is lithium titanate; if the battery is a sodium-ion battery, the titanate is sodium titanate. However, the present application is not limited to these materials, and other conventional materials suitable as negative electrode active materials for a battery may also be used. These negative electrode active materials may be used alone or in combination with one or more of them.

[0079] 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 materials: 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).

[0080] 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 the following materials: superconducting carbon, acetylene carbon black, carbon black, Ketjen black, a carbon dot, a carbon nanotube, graphene, and a carbon nanofiber.

[0081] In some embodiments, the negative electrode active material layer may optionally also include other excipients, such as a thickening agent (e.g. sodium carboxymethylcellulose (CMC-Na)).

[0082] In some embodiments, the negative electrode sheet can be produced in the following manner: the above-mentioned components for producing 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, which is applied to the negative electrode current collector, and after drying, cold pressing, and other processes, the negative electrode sheet can be obtained.

[0083] According to some embodiments of the present application, the negative electrode sheet comprises a negative electrode current collector and a negative electrode film layer, wherein the negative electrode current collector comprises a negative electrode main body and a negative electrode tab section, the negative electrode tab section extending from the negative electrode main body section, the battery cell comprising a housing body, a first end cap arrangement and a second end cap arrangement, wherein the housing body, the first end cap arrangement and the second end cap arrangement define a receiving cavity, the first end cap arrangement comprising a first end cap and at least one positive electrode terminal, the positive electrode main body section being electrically connected to the positive electrode terminal via the positive electrode tab section;and / or wherein the second end cover arrangement comprises a second end cover and at least one negative electrode terminal, wherein the negative electrode main body section is electrically connected to the negative electrode terminal via the negative electrode tab section.

[0084] Specifically, the battery cell comprises a housing body, a first end-cap assembly, and a second end-cap assembly. The first end-cap assembly comprises a first end cap, and the second end-cap assembly comprises a second end cap, wherein, with reference to Fig.3 the first end cover arrangement and the second end cover arrangement can be arranged at both ends of the housing body 11 along its longitudinal direction, or wherein the first end cover arrangement and the second end cover arrangement can be arranged at both ends of the housing body 11 along its width direction.Specifically, if the housing body 11 has openings at both ends along its longitudinal direction, the first end cap assembly and the second end cap assembly can be arranged at both ends of the housing body 11 along its longitudinal direction and are suitable for covering the respective openings. Similarly, if the housing body 11 has openings at both ends along its transverse direction to isolate the internal environment of the battery cell from the external environment, the first end cap assembly and the second end cap assembly can be arranged at both ends along its transverse direction and are suitable for covering the respective openings. The shape of the first end cap assembly and the second end cap assembly can be adapted to the shape of the housing body 11 to fit it.

[0085] In some embodiments, the first end cover arrangement and the second end cover arrangement can be arranged at both ends of the housing body 11 along its longitudinal direction, i.e., the first end cover arrangement and the second end cover arrangement are arranged on the smaller side surface of the housing body 11, thereby saving space of the battery cell along the width direction, which allows for a wider electrode sheet and improves the energy density of the battery cell.

[0086] In some embodiments, the housing body 11 is joined by bending and subsequent welding, the weld traces being integrated on the smaller side surface of the housing body 11 extending along the longitudinal direction, which helps to reduce the problem of cracking in the weld area caused by the expansion of the battery cell along the thickness direction and to improve the reliability of the housing body 11.

[0087] The first and second end caps can each be made of a material with a specific hardness and strength (such as an aluminum alloy), thus increasing their strength and reducing deformation when compressed, thereby improving the battery cell's safety performance. In some embodiments, the first and second end caps can optionally be made of steel.

[0088] For example, the first end cover assembly, the second end cover assembly, and the housing body can be independent components.

[0089] For example, the first end cap assembly, the second end cap assembly, and the housing body can be integrated. Specifically, the first end cap assembly or the second end cap assembly and the housing body can form a common connecting body before the electrode assembly and other components are inserted into the housing body, wherein, after the electrode assembly and other components have been inserted into the housing body 11, the second end cap assembly or the first end cap assembly then covers the opening of the housing body along the longitudinal or transverse direction, respectively.

[0090] According to some embodiments of the present application, with reference to Fig. 4, Fig. 5, Fig. 6 to Fig. 7, the first end cover arrangement 12 comprises a first end cover 121 and a first electrode connection 122.

[0091] Referring to the schematic representation of the disassembly of the first end cover assembly 12 from Fig. 5 comprises the first end cover assembly 12 in some embodiments a first end cover 121, a first electrode connection 122, a first insulating element 123, a first sealing element 124, a first positioning element 125, a second insulating element 126 and a rivet block 127 and is to the one shown in Fig. The first end cover arrangement shown in section 4 is assembled.

[0092] In some embodiments, Fig. 7 a schematic cross-sectional view from Fig. 6 along AA' direction, in combination with Fig. 5 and Fig.As can be seen in Figure 7, a first opening 1211 is provided on the first end cover 121 and the first electrode connection 122 passes through the first end cover 121, wherein a first insulating element 123 is provided between the first end cover 121 and the first electrode connection 122, wherein this assembly method serves, on the one hand, to separate the electrical connection components in the housing body 11 from the first end cover 121 and, on the other hand, to keep the first electrode connection 122 and the first end cover 121 in an insulated state in order to reduce the risk of short circuits, wherein a second opening 1231 is provided on the first insulating element 123, wherein the first electrode connection 122 is passed through the second opening 1231 and the first opening 1211 successively, wherein a first sealing element 124 is provided between the first opening 1211 and the first electrode connection 122 for insulation and sealing.wherein a through-hole is provided on the first sealing element 124 through which the first electrode connection 122 can be passed, wherein a second insulating element 126 and a rivet block 127 are provided on the side of the first end cap 121 facing away from the electrode arrangement, wherein through-holes are also provided on the second insulating element 126 and the rivet block 127, wherein the first electrode connection 122 is passed through the through-holes of the second insulating element 126 and the rivet block 127 successively, wherein the second insulating element 126 serves to insulate the first electrode connection 122 from the first end cap 121 and the rivet block 127 is used to fasten the first electrode connection 122 to the first end cap 121.

[0093] Referring to Fig.5 In some embodiments, the first end cover arrangement further comprises a first positioning element 125, wherein the first positioning element 125 comprises at least two elements to prevent deflection of the first electrode connection 122 and to improve the strength of the first electrode connection 122.

[0094] Referring to Fig. 5 the first end cover arrangement 12 in some embodiments includes a liquid injection hole 1212 for injecting electrolyte into the receiving cavity of the housing body 11.

[0095] Referring to the Fig. 8, Fig. 9, Fig. 10 to Fig. 11 includes the second end cover arrangement 13, a second end cover 131 and a second electrode connection 132.

[0096] Referring to the schematic representation of the disassembly of the second end cover assembly 13 from Fig.9 comprises the second end cover assembly 13 in some embodiments a second end cover 131, a second electrode connection 132, a third insulating element 133, a second sealing element 134, a fourth insulating element 136, a rivet block 127 and a second positioning element 135 and is to the one in Fig. 8 shown second end cover arrangement 13 assembled.

[0097] In some embodiments, Fig. 11 a schematic cross-sectional view from Fig. 10 along the BB' direction, in combination with Fig. 9 and Fig.As can be seen in Figure 11, a third opening 1311 is provided on the second end cover 131, and the second electrode connection 132 passes through the second end cover 131, wherein a third insulating element 133 is provided between the second end cover 131 and the second electrode connection 132, this type of assembly serves, on the one hand, to separate the electrical connection components in the housing body 11 from the second end cover 131 and, on the other hand, to keep the second electrode connection 132 and the second end cover 131 in an insulated state in order to reduce the risk of a short circuit, wherein a fourth opening 1331 is provided on the third insulating element 133, wherein the second electrode connection 132 is passed through the fourth opening 1331 and the third opening 1311 successively, wherein a second sealing element 134 is provided between the third opening 1311 and the second electrode connection 132 for insulation and sealing.wherein a through-hole is provided on the second sealing element 134 through which the second electrode connection 132 can be passed, wherein a fourth insulating element 136 and a rivet block 127 are provided on the side of the second end cover 131 facing away from the electrode arrangement, wherein through-holes are also provided on the fourth insulating element 136 and the rivet block 127, wherein the second electrode connection 132 is passed through the through-holes of the fourth insulating element 136 and the rivet block 127 successively, wherein the fourth insulating element 136 serves to insulate the second electrode connection 132 from the second end cover 131 and the rivet block 127 is used to fasten the second electrode connection 132 to the second end cover 131.

[0098] Referring to Fig.9 In some embodiments, the second end cover arrangement 13 further comprises a second positioning element 135, wherein the second positioning element 135 comprises at least two elements to prevent the deflection of the second electrode connection 132 and to improve the force strength of the second electrode connection 132.

[0099] According to some embodiments of the present application, with reference to Fig. 8, Fig. 9, Fig. 10 to Fig. 11, the second end cover 131 is provided with a pressure relief mechanism 137, wherein the pressure relief mechanism 137 can release the internal pressure of the housing body when the internal pressure of the housing body exceeds a threshold value.

[0100] For example, the pressure relief mechanism 137 and the second end cap 131 are two separate components that are molded separately and then assembled together. The pressure relief mechanism 137 can be an explosion-proof disc, an explosion-proof valve, or a safety valve, and can be attached to the second end cap 131 by gluing, welding, or the like. When the internal pressure of the battery cell reaches a threshold, the pressure relief mechanism 137 opens at least part of the pressure relief port, and the drain medium inside the battery cell is discharged through the pressure relief port to relieve the pressure inside the battery cell.

[0101] According to some embodiments of the present application, the first end cover arrangement comprises one positive electrode terminal and one negative electrode terminal, wherein the positive electrode main body section is electrically connected to the positive electrode terminal via the positive electrode tab section and the negative electrode main body section is electrically connected to the negative electrode terminal via the negative electrode tab section.

[0102] According to some embodiments of the present application, the second end cover arrangement comprises one positive electrode terminal and one negative electrode terminal, wherein the positive electrode body section is electrically connected to the positive electrode terminal via the positive electrode tab section, and the negative electrode body section is electrically connected to the negative electrode terminal via the negative electrode tab section. This improves the current-carrying capacity of the battery cell.

[0103] Referring to Fig.12, the first end cover assembly 12 and the second end cover assembly 13 are arranged at both ends of the housing body 11 along its longitudinal direction, wherein the first end cover assembly 12 comprises a positive electrode terminal and a negative electrode terminal, and wherein the second end cover assembly comprises a positive electrode terminal and a negative electrode terminal.

[0104] Referring to Fig. 13, Fig. 14, Fig. 15 to Fig.16, the first end cover arrangement 12 comprises in particular a first end cover 121 and two electrode terminals with opposite polarities (a first electrode terminal 122 and a second electrode terminal 132), wherein if the first electrode terminal 122 is a positive electrode terminal, the second electrode terminal 132 is a negative electrode terminal; if the first electrode terminal 122 is a negative electrode terminal, the second electrode terminal is a positive electrode terminal.

[0105] Referring to the schematic representation of the disassembly of the first end cover assembly 12 from Fig.14 The first end cover assembly 12 in some embodiments comprises a first end cover 121, a first electrode connection 122, a second electrode connection 132, a first insulating element 123, two first sealing elements 124, two second insulating elements 126, two rivet blocks 127 and four first positioning elements 125 and is to be shown in Fig. The first end cover arrangement shown in section 13 is assembled.

[0106] In some embodiments, Fig. 16 a schematic cross-sectional view from Fig. 15 along the CC' direction, in combination with Fig. 14 and Fig.As can be seen in Figure 16, two first openings 1211 are provided on the first end cover 121, and the first electrode connection 122 and the second electrode connection 132 each extend through the first end cover 121, wherein a first insulating element 123 is provided between the first end cover 121 and the first electrode connection 122 and the second electrode connection 132, wherein this type of assembly serves, on the one hand, to separate the electrical connection components in the housing body 11 from the first end cover 121 and, on the other hand, to keep the first electrode connection 122, the second electrode connection 132, and the first end cover 121 in an insulated state in order to reduce the risk of short circuits, wherein two second openings 1231 are provided on the first insulating element 123.wherein the first electrode connection 122 and the second electrode connection 132 are each successively passed through the correspondingly arranged second opening 1231 and the first opening 1211, wherein a first sealing element 124 is provided between the first opening 1211 and the first electrode connection 122 and the second electrode connection 132 for insulation and sealing, wherein a through-hole is provided on the first sealing element 124 through which the first electrode connection 122 and the second electrode connection 132 can pass, wherein two second insulating elements 126 and two rivet blocks 127 are provided on the side of the first end cover 121 facing away from the electrode arrangement, wherein through-holes are also provided on the second insulating element 126 and the rivet block 127,wherein the first electrode connection 122 and the second electrode connection 132 are successively passed through the appropriately arranged through-holes of the second insulating element 126 and the rivet block 127, the second insulating element 126 serving to insulate the electrode connection from the first end cap 121 and the rivet block 127 being used to fasten the electrode connection to the first end cap 121.

[0107] Referring to the Fig. 17, Fig. 18, Fig. 19 to Fig.The second end cover assembly 13 comprises a second end cover 131 and two electrode terminals with opposite polarities (a first electrode terminal 122 and a second electrode terminal 132). If the first electrode terminal 122 is a positive electrode terminal, the second electrode terminal 132 is a negative electrode terminal; if the first electrode terminal 122 is a negative electrode terminal, the second electrode terminal is a positive electrode terminal.

[0108] Referring to the schematic representation of the disassembly of the second end cover assembly 13 from Fig.18 The second end cover assembly 13 in some embodiments comprises a second end cover 131, a first electrode connection 122, a second electrode connection 132, a third insulating element 133, two second sealing elements 134, a fourth insulating element 136, a rivet block 127 and a second positioning element 135 and is to the one shown in Fig. The second end cover arrangement shown in 17 is assembled.

[0109] In some embodiments, Fig. 20 a schematic cross-sectional view from Fig. 19 along the DD' direction, in combination with Fig. 18 and Fig.As can be seen in Figure 20, two third openings 1311 are provided on the second end cover 131, and the first electrode connection 122 and the second electrode connection 132 extend through the second end cover 131, wherein a third insulating element 133 is provided between the second end cover 131 and the first electrode connection 122 and the second electrode connection 132, wherein this type of assembly serves, on the one hand, to separate the electrical connection components in the housing body 11 from the second end cover 131 and, on the other hand, to keep the first electrode connection 122 and the second electrode connection 132 and the second end cover 131 in an insulated state in order to reduce the risk of short circuits, wherein two fourth openings 1331 are provided on the third insulating element 133.wherein the first electrode connection 122 and the second electrode connection 132 are successively passed through the correspondingly arranged fourth opening 1331 and the third opening 1311, wherein a second sealing element 134 is provided between the third opening 1311 and the first electrode connection 122 and the second electrode connection 132 for insulation and sealing, wherein a through-hole is provided on the second sealing element 134 through which the first electrode connection 122 and the second electrode connection 132 can pass, wherein two fourth insulating elements 136 and two rivet blocks 127 are provided on the side of the second end cover 131 facing away from the electrode arrangement, wherein through-holes are also provided on the fourth insulating element 136 and the rivet block 127,wherein the first electrode connection 122 and the second electrode connection 132 are successively passed through the correspondingly arranged through-holes of the fourth insulating element 136 and the rivet block 127, the fourth insulating element 136 serving to insulate the electrode connection from the second end cap 131 and the rivet block 127 being used to fasten the electrode connection to the second end cap 131.

[0110] According to some embodiments of the present application, the first end cover arrangement and the second end cover arrangement are arranged at both ends of the housing body, wherein the electrode terminals with the same polarities are arranged offset along the longitudinal direction of the battery cell on the first end cover arrangement and on the second end cover arrangement.

[0111] According to some embodiments of the present application, the electrode terminals with the same polarities are arranged diagonally along the longitudinal direction of the battery cell.

[0112] This can reduce the temperature increase of the battery cell during charging and thus reduce the impedance of the battery cell.

[0113] Referring to Fig.21 The electrode arrangement 20 comprises four electrode tabs, wherein two electrode tabs extend lengthwise from one end of the electrode arrangement 20, namely a first positive electrode tab 2121 and a first negative electrode tab 31, while two electrode tabs extend lengthwise from the other end of the electrode arrangement 20, namely a second positive electrode tab 2122 and a second negative electrode tab 32.The first positive electrode tab 2121 is electrically connected to the first electrode terminal 122 on the first end cap, while the first negative electrode tab 31 is electrically connected to the second electrode terminal 132 on the first end cap, the second positive electrode tab 2122 is electrically connected to the first electrode terminal 122 on the second end cap 131, and the second negative electrode tab 32 is electrically connected to the second electrode terminal 132 on the second end cap 131. This arrangement places the electrode terminals with opposite polarities diagonally along the length of the battery cell, which can reduce the temperature rise of the battery cell during charging and thus lower the impedance of the battery cell.

[0114] Referring to Fig.22 The electrode arrangement 20 comprises four electrode tabs, wherein two electrode tabs extend longitudinally from one end of the electrode arrangement 20, namely a first positive electrode tab 2121 and a first negative electrode tab 31, while two electrode tabs extend longitudinally from the other end of the electrode arrangement 20, namely a second positive electrode tab 2122 and a second negative electrode tab 32. The two positive electrode tabs at both ends of the electrode arrangement 20 are arranged asymmetrically in the longitudinal direction, and the two negative electrode tabs at both ends of the electrode arrangement 20 are arranged asymmetrically in the longitudinal direction.The first positive electrode tab 2121 is electrically connected to the first electrode terminal 122 on the first end cap, while the first negative electrode tab 31 is electrically connected to the second electrode terminal 132 on the first end cap, the second positive electrode tab 2122 is electrically connected to the first electrode terminal 122 on the second end cap 131, and the second negative electrode tab 32 is electrically connected to the second electrode terminal 132 on the second end cap 131. This arrangement places the electrode terminals with the same polarity diagonally along the length of the battery cell, which can increase the current-carrying capacity of the battery cell while simultaneously reducing internal wiring, thus simplifying assembly.

[0115] According to some embodiments of the present application, the battery cell is configured to charge from 10% SOC to 80% SOC in a charging time of 5 to 10.5 minutes. This improves the fast-charging performance of the battery cell.

[0116] The present application is not subject to any special restrictions regarding the type of separator and any known porous separator with good chemical and mechanical stability may be selected and used.

[0117] In some embodiments, the separator material can be selected from at least one of the following: 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 the individual layers can be the same or different without any particular restriction.

[0118] A second aspect of the present application relates to a battery device comprising the battery cell provided by the first aspect of the present application, wherein the battery device is at least one of the following: battery module, battery pack and energy storage device.

[0119] The third aspect of the present application provides a power-consuming device comprising the battery cell provided by the first aspect of the present application or the battery device provided by the second aspect of the present application, wherein the battery cell or the battery device is used to provide electrical energy. The power-consuming devices may 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.

[0120] Depending on its usage requirements, a battery module or battery pack can be selected as the power-consuming device.

[0121] Fig.Figure 23 shows an example of a power-consuming device. This device could be a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, etc. To meet the power-consuming device's requirements for high performance and high battery energy density, a battery pack or battery module can be used.

[0122] Another example of a device could be a mobile phone, a tablet computer, a laptop computer, etc. The device typically needs to be light and thin, and a battery can be used as a power source.

[0123] To clarify the technical problems, solutions, and advantages addressed by the embodiments of this application, further detailed explanations are provided below with reference to the embodiments and drawings. Obviously, the described embodiments represent only a portion of the embodiments of this application, not all of them. The following description of at least one exemplary embodiment serves only for illustration and is not intended to limit the present application or its applications in any way. Based on the embodiments of this application, all other embodiments that could be obtained by those skilled in the art without creative effort fall within the scope of protection of this application. Example 11. Positive electrode sheet

[0124] The positive electrode sheet comprises an aluminum foil of the positive electrode current collector, wherein a positive electrode film layer is located on both surfaces of the aluminum foil, with the compaction density at 100% SOC being 2.65 g / cm³. 3 is, where the coating weight of the one-sided positive electrode film layer is 290 mg / 1540.25 mm² 2the positive electrode film layer has a size of 200 mm, the positive electrode film layer comprising, based on the total mass of the one-sided positive electrode film layer, a material of lithium iron phosphate with a mass fraction of 95.8%, a lithium supplement Li5FeO4 with a mass fraction of 0.9%, a conductive material of carbon black with a mass fraction of 1.1%, and a binder of polyvinylidene fluoride (PVDF) with a mass fraction of 2.2%, the surface of the lithium iron phosphate having a carbon coating layer, and the mass fraction of the carbon coating layer being 1.18% based on the total mass of the lithium iron phosphate. 2. Negative electrode sheet

[0125] The negative electrode sheet comprises a copper foil of the negative electrode current collector, wherein a negative electrode film layer is located on both surfaces of the copper foil, with a compaction density of 1.56 g / cm³. 3 is, where the coating weight of the one-sided negative electrode film layer is 138 mg / 1540.25 mm² 2 the negative electrode film layer comprises, in relation to the total mass of the one-sided negative electrode film layer, an artificial graphite with a mass fraction of 96%, a conductive agent made of carbon black with a mass fraction of 1.1%, a binder made of styrene-butadiene rubber (SBR) with a mass fraction of 1.4%, and a thickening agent made of sodium carboxymethylcellulose (CMC-Na) with a mass fraction of 1.5%. 3. Electrolyte

[0126] The electrolyte comprises a solvent, an electrolyte salt, and an additive, wherein the solvent comprises ethylene carbonate (EC), dimethyl carbonate (DMC), and ethyl acetate, wherein the electrolyte salt is lithium hexafluorophosphate and lithium bis(fluorosulfonyl)imide (LiFSI), and wherein the additive comprises vinylene carbonate (VC), fluoroethylene carbonate (FEC), ethylene sulfite (ES), and lithium difluorooxalatoborate (LiDFOB), wherein, based on the total mass of the electrolyte, the mass fraction of EC is 28.9%, the mass fraction of DMC is 45.4%, the mass fraction of ethyl acetate is 8.3%, the mass fraction of lithium hexafluorophosphate is 8.3%, the mass fraction of LiFSI is 4.2%, the mass fraction of VC is 3%, the mass fraction of FEC is 1%, the mass fraction of ES is 0.5%, and the mass fraction of LiDFOB is 0.5%, wherein the density of the electrolyte is 1.22 g / mL. Viscosity 3.19 mPa·s, conductivity 11 mS / cm. 4. Separator

[0127] Polypropylene film, 12 µm thick. 5. Battery cell

[0128] The battery cell comprises a housing body, a first end cap assembly, a second end cap assembly, an electrode assembly, and an electrolyte, wherein the first end cap assembly and the second end cap assembly are located at both ends of the longitudinal direction of the housing body, wherein the assembly of the first end cap assembly is arranged in Fig. 4 and the construction of the second end cover arrangement in Fig.8, that is, the first end cover arrangement and the second end cover arrangement each comprise a positive electrode terminal, wherein the electrode arrangement and the electrolyte are arranged in a receiving cavity formed by the housing body and the end cover, wherein the electrode arrangement is a laminated electrode arrangement produced by lamination of the above-mentioned positive electrode sheet, separator and negative electrode sheet, wherein a positive electrode tab extends along the longitudinal direction of the electrode arrangement at one end and a negative electrode tab extends at the other end, wherein the positive electrode tab is electrically connected to the positive electrode terminal and the negative electrode tab is electrically connected to the negative electrode terminal.

[0129] The battery housing body has a housing length of 245 mm, a width of 104.5 mm and a thickness of 15.7 mm. Performance test 1. Charging time

[0130] Calculating the time required to charge a battery cell from 10% SOC to 80% SOC, where the charging process proceeds as follows: Charging from 0% SOC to 10% SOC at a constant current of 1°C; charging from 10% SOC to 30% SOC at a constant current of 7.0°C; charging from 30% SOC to 35% SOC at a constant current of 6.2°C; charging from 35% SOC to 40% SOC at a constant current of 5.7°C; charging from 40% SOC to 45% SOC at a constant current of 5.2°C; charging from 45% SOC to 50% SOC at a constant current of 4.8°C; charging from 50% SOC to 55% SOC at a constant current of 4.6°C; charging from 55% SOC to 60% SOC at a constant current of 4.4°C; charging from 60% SOC to 65% SOC at a constant current of 4.2°C; charging from 65% SOC to 70% SOC at a constant current of 3.9°C. Charging from 70% SOC to 75% SOC at a constant current of 3.5C; charging from 75% SOC to 80% SOC at a constant current of 3.0C, where the sum of the total time of each charging period is the charging time. 2. Cycle lifespan at high temperatures

[0131] At an ambient temperature of 45 °C, the cell is charged stepwise to 3.8 V (step charge), charged at constant voltage to 0.05 C, left to rest for 30 minutes, discharged at constant current of 0.5 C to 2.5 V and left to rest for 30 minutes, which is one charge and discharge cycle, whereby the above charge and discharge cycles are repeated until the capacity of the battery cell is 80% of the initial capacity, whereby the number of charge and discharge cycles is obtained, which therefore represents the lifespan of the battery cell at high temperatures.

[0132] The charging steps with Step Charge are as follows: Charging from 0% SOC to 10% SOC at a constant current of 1°C; charging from 10% SOC to 30% SOC at a constant current of 7.0°C; charging from 30% SOC to 35% SOC at a constant current of 6.2°C; charging from 35% SOC to 40% SOC at a constant current of 5.7°C; charging from 40% SOC to 45% SOC at a constant current of 5.2°C; charging from 45% SOC to 50% SOC at a constant current of 4.8°C; charging from 50% SOC to 55% SOC at a constant current of 4.6°C; charging from 55% SOC to 60% SOC at a constant current of 4.4°C; charging from 60% SOC to 65% SOC at a constant current of 4.2°C; charging from 65% SOC to 70% SOC at a constant current of 3.9°C. Charging from 70% SOC to 75% SOC at a constant current of 3.5C; charging from 75% SOC to 80% SOC at a constant current of 3.0C; charging from 80% SOC to 100% SOC at a constant current of 0.33C. 3. Energy density

[0133] Charged at 25 °C with a constant current of 0.33 C to 3.8 V, then charged with a constant voltage of 3.8 V to 0.05 C and left to rest for 30 minutes, then discharged with a constant current of 0.33 C to 2.0 V, the discharge capacity A0 at this time being recorded in Ah, the discharge platform voltage being calculated in V, the length, width and height of the battery cell being measured with calipers, the volume of the battery cell V0 being calculated in L, and the volume energy density of the battery cell VED = (A0 x discharge platform voltage) / V0 / 1000 in Wh / L.

[0134] In the present application, the length of the battery cell minus the size of the positive electrode film layer is 45 mm, the width of the battery cell is 104.5 mm, the thickness of the battery cell is 15.7 mm, the discharge capacity A0 is 62.3 Ah and the discharge platform voltage is 3.2 V. Example 2

[0135] The manufacturing process of the battery cell is the same as in embodiment 1, except that the size of the positive electrode film layer is 400 mm. Example 3

[0136] The manufacturing process of the battery cell is the same as in embodiment 1, except that the size of the positive electrode film layer is 500 mm. Example 4

[0137] The manufacturing process of the battery cell is the same as in embodiment 1, except that the size of the positive electrode film layer is 650 mm. Example 5

[0138] The manufacturing process of the battery cell is the same as in embodiment 1, except that the size of the positive electrode film layer is 700 mm. Comparative example 1

[0139] The manufacturing process of the battery cell is the same as in embodiment 1, except that the size of the positive electrode film layer is 150 mm. Comparative example 2

[0140] The manufacturing process of the battery cell is the same as in embodiment 1, except that the size of the positive electrode film layer is 800mm.

[0141] The detailed differences between the battery cells in embodiments 2 to 5 and comparison examples 1 to 2, as well as the test results, are listed in Table 1. Table 1 Positive electrode sheet Battery cell Size of the positive electrode film layer (mm) Charging time (min) Cycle life with 45°C step charge at high temperatures at 80% SOH A0 (Ah) Energy density (Wh / L) Comparative example 1 150 8,9 2205 31,86 318,7 Comparative example 2 800 11,5 1807 169,67 391,6 Example 1 200 9 2201 42,51 338,4 Example 2 400 9,3 2144 83,99 368,1 Example 3 500 9,7 2065 105,49 377,5 Example 4 650 10 2023 137,62 386,2 Example 5 700 10,5 1978 148,93 389,9

[0142] A comparison between embodiments 1 to 5 and comparative examples 1 and 2 shows that by increasing the size of the positive electrode film layer from 200 mm to 700 mm² and simultaneously combining it with the electrolyte containing the chain-like carboxylate, the energy density, fast-charging performance, and cycle life of the battery cell can be improved. If the size of the positive electrode film layer is too small, the energy density of the battery cell is relatively low, although the charging time is short; if the size of the positive electrode film layer is too large, the temperature of the battery cell rises relatively quickly due to the relatively long electrode sheet, and the internal resistance is relatively high, which shortens the battery cell's lifespan, even though the energy density of the battery cell is high. Example 6

[0143] The manufacturing process of the battery cell is the same as in embodiment 4, except that the mass fraction of ethyl acetate is 5%, the mass fraction of EC is 28.9% and the mass fraction of DMC is 48.6%. Example 7

[0144] The manufacturing process of the battery cell is the same as in embodiment 4, except that the mass fraction of ethyl acetate is 6.6%, the mass fraction of EC is 28.9%, and the mass fraction of DMC is 47%. Example 8

[0145] The manufacturing process of the battery cell is the same as in embodiment 4, except that the mass fraction of ethyl acetate is 24.8%, the mass fraction of EC is 28.9%, and the mass fraction of DMC is 28.9%. Example 9

[0146] The manufacturing process of the battery cell is the same as in embodiment 4, except that the mass fraction of ethyl acetate is 40.8%, the mass fraction of EC is 28.5%, the mass fraction of DMC is 12.2%, and the mass fraction of VC in the additive is 4%. Example 10

[0147] The manufacturing process of the battery cell is the same as in embodiment 4, except that the mass fraction of ethyl acetate is 56.4%, the mass fraction of EC is 24.2%, and the mass fraction of VC in the additive is 5%, and there is no DMC. Example 11

[0148] The manufacturing process of the battery cell is the same as in embodiment 4, except that the carboxylate is methyl acetate. Comparative example 3

[0149] The manufacturing process of the battery cell is the same as in embodiment 4, except that the mass fraction of ethyl acetate is 61.9% and the mass fraction of EC is 20.6%, and that there is no DMC. Comparative example 4

[0150] The manufacturing process of the battery cell is the same as in embodiment 4, except that no chain-like carboxylate is included in the electrolyte, and that the mass fraction of EC is 29.6%, the mass fraction of DMC is 54.9%, and the mass fraction of VC in the additive is 1%.

[0151] The detailed differences between the battery cells in embodiments 6 to 11 and comparison examples 3 and 4, as well as the test results, are listed in Table 2. Table 2

[0152] From the comparison of embodiments 6 to 10 with comparative examples 3 and 4, it can be seen that by adjusting the carboxylate content in the electrolyte, an electrolyte with relatively high conductivity can be obtained, thereby reducing the charging time and improving the fast-charging performance of the battery. However, if the carboxylate content is too high, the electrolyte can easily release gases at high temperatures, releasing acid that corrodes the SEI film, thus shortening the service life of the battery cell at high temperatures.

[0153] A comparison of embodiments 6 to 10 with comparative example 1 shows that the energy density of the battery cells is also improved. A comparison with comparative example 2 shows that the energy density of the battery cells is also improved.

[0154] As can be seen from embodiment 11, different types of carboxylates can improve the ionic conductivity of the electrolyte. Example 12

[0155] The manufacturing process of the battery cell is the same as in embodiment 4, except that the compaction density of the positive electrode film layer is 2.5 g / cm³. 3 amounts. Example 13

[0156] The manufacturing process of the battery cell is the same as in embodiment 4, except that the compaction density of the positive electrode film layer is 2.6 g / cm³. 3 amounts. Example 14

[0157] The manufacturing process of the battery cell is the same as in embodiment 4, except that the compaction density of the positive electrode film layer is 2.7 g / cm³. 3 amounts. Example 15

[0158] The manufacturing process of the battery cell is the same as in embodiment 4, except that the coating weight of the positive electrode film layer is 220 mg / 1540.25 mm². 2 amounts. Example 16

[0159] The manufacturing process of the battery cell is the same as in embodiment 4, except that the coating weight of the positive electrode film layer is 260 mg / 1540.25 mm². 2 amounts. Example 17

[0160] The manufacturing process of the battery cell is the same as in embodiment 4, except that the coating weight of the positive electrode film layer is 300 mg / 1540.25 mm². 2 amounts. Example 18

[0161] The manufacturing process of the battery cell is the same as in embodiment 4, except that the coating weight of the positive electrode film layer is 340 mg / 1540.25 mm². 2 amounts.

[0162] The detailed differences between the battery cells in embodiments 12 to 18 and the test results are listed in Table 3. Table 3 Positive electrode sheet Battery cell Size of the positive electrode film layer (mm) Density of the positive electrode film layer (g / cm²) 3 ) Coating weight (mg / 1540.25 mm²) 2 ) Types of Mass fraction of lithium supplement (%) Charging time (min) Cycle life with 45 °C step charge at high temperatures at 80% SOH A0(Ah) Energy density (Wh / L) Example 12 650 2,5 290 Li5FeO4 0,9 10,2 1980 134,42 377,2 Example 13 650 2,6 290 Li5FeO4 0,9 10 2009 136,67 393,6 Example 14 650 2,7 290 Li5FeO4 0,9 10,1 2020 138,88 389,7 Example 15 650 2,65 220 Li5FeO4 0,9 7,1 2012 134,73 378,1 Example 16 650 2,65 260 Li5FeO4 0,9 8,6 2060 140,06 393,1 Example 17 650 2,65 300 Li5FeO4 0,9 9,2 2024 143,31 402,2 Example 18 650 2,65 340 Li5FeO4 0,9 10,0 1981 146,34 410,7

[0163] From the embodiments 12 to 18 it can be seen that by adjusting the compaction density and the coating weight of the positive electrode film layer, the charging time and energy density of the battery cell can be optimized and a battery cell with both excellent fast charging performance and relatively high energy density is obtained. Example 19

[0164] The manufacturing process of the battery cell is the same as in embodiment 4, except that the lithium supplement is lithium nickel oxide. Example 20

[0165] The manufacturing process of the battery cell is the same as in embodiment 4, except that the mass fraction of Li5FeO4 is 0.5% and the mass fraction of the material made from lithium iron phosphate is 96.2%. Example 21

[0166] The manufacturing process of the battery cell is the same as in embodiment 4, except that the mass fraction of Li5FeO4 is 1.5% and the mass fraction of the material made from lithium iron phosphate is 95.2%. Example 22

[0167] The manufacturing process of the battery cell is the same as in embodiment 4, except that the mass fraction of Li5FeO4 is 2.5% and the mass fraction of the material made from lithium iron phosphate is 94.2%. Example 23

[0168] The manufacturing process of the battery cell is the same as in embodiment 4, except that the mass fraction of Li5FeO4 is 2.8% and the mass fraction of the material made from lithium iron phosphate is 93.9%.

[0169] The detailed differences between the battery cells in embodiments 19 to 23 and the test results are listed in Table 4. Table 4 Positive electrode sheet Battery cell Types of lithium supplement Mass fraction of the lithium supplement (%) Charging time (min) Cycle life with 45 °C step charge at high temperatures at 80% SOH A0(Ah) Energy density (Wh / L) Example 19 Lithium nickel oxide 0,9 10,1 2042 137,62 386,2 Example 20 Li5FeO4 0,5 10,0 2009 136,81 383,9 Example 21 Li5FeO4 1,5 9,8 2161 135,04 379,0 Example 22 Li5FeO4 2,5 9,8 2202 133,28 374,0 Example 23 Li5FeO4 2,8 9,8 2226 132,87 372,9

[0170] From the embodiments 20 to 23 it can be seen that by adjusting the content of the lithium supplement in the positive electrode film layer, the charging time, the cycle life and the energy density of the battery cell can be optimized simultaneously, and a battery cell with excellent overall properties is obtained.

[0171] From embodiment 19 it can be seen that different types of lithium supplementation layer can all achieve the effect of lithium supplementation.

[0172] Finally, it should be noted that the above embodiments serve only to illustrate the technical solutions of the present application and do not limit them. Although the present application has been described in detail with reference to the above embodiments, it should be clear to those skilled in the art that the technical solutions described in the above embodiments can be modified or some or all of the technical features can be replaced by equivalent features without such modifications or replacements altering the essential character of the corresponding technical solutions beyond the scope of the technical solutions of the embodiments of the present application, and all of them should fall within the scope of the claims and the description of the present application.In particular, the technical features mentioned in the individual embodiments can be combined in any way, provided there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions that fall within the scope of the claims.

Claims

[1] Battery cell comprising: a casing body, an electrode arrangement and an electrolyte, 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 film layer, wherein the positive electrode current collector comprises a positive electrode main body section and a positive electrode tab section, wherein the positive electrode tab section extends from the positive electrode main body section, wherein the positive electrode film layer is located on at least one side of the positive electrode main body section, wherein the positive electrode film layer comprises a lithium-containing phosphate, and wherein the positive electrode film layer has a size of 200 mm to 700 mm along a longitudinal direction of the positive electrode sheet; wherein the negative electrode sheet comprises a negative electrode current collector and a negative electrode film layer, wherein the negative electrode current collector comprises a negative electrode main body section and a negative electrode tab section, wherein the negative electrode tab section extends from the negative electrode main body section, wherein the negative electrode film layer is located on at least one side of the positive electrode main body section, and wherein the negative electrode film layer comprises graphite; wherein the electrolyte comprises a chain-like carboxylate, wherein a mass fraction of the chain-like carboxylate relative to a total mass of the electrolyte is 5% to 60%. [2] Battery cell according to claim 1, wherein the size of the positive electrode film layer is 400 mm to 650 mm along the longitudinal direction of the positive electrode sheet. [3] Battery cell according to claim 1 or 2, wherein the mass fraction of the chain-like carboxylate is 8% to 30% in relation to the total mass of the electrolyte. [4] Battery cell according to any one of claims 1 to 3, wherein the electrolyte has a conductivity of 9.5 mS / cm to 19 mS / cm at room temperature. [5] Battery cell according to any one of claims 1 to 4, wherein the electrolyte has a conductivity of 9.7 mS / cm to 13.5 mS / cm at room temperature. [6] Battery cell according to any one of claims 1 to 5, wherein the electrolyte has a viscosity of 2 mPa·s to 5 mPa·s at room temperature. [7] Battery cell according to any one of claims 1 to 6, wherein the electrolyte has a density of 1.05 g / mL to 1.35 g / mL at room temperature. [8] Battery cell according to any one of claims 1 to 7, wherein the chain-like carboxylate comprises a compound represented by formula I: wherein R1 comprises one or more of the following: a hydrogen atom, a C1-C5 alkyl group and a C1-C5 haloalkyl group, while R2 comprises one or more of the following: a C1-C5 alkyl group and a C1-C5 haloalkyl group. [9] Battery cell according to claim 8, wherein R1 comprises one or more of the following: a hydrogen atom, a C1-C3 alkyl group and a C1-C3 haloalkyl group; and / or wherein R2 comprises one or more of the following substances: a C1-C3 alkyl group and a C1-C3 haloalkyl group. [10] Battery cell according to any one of claims 1 to 9, wherein the chain-like carboxylate comprises one or more of the following formulas: [11] Battery cell according to one of claims 1 to 10, wherein a one-sided coating weight of the positive electrode film layer is 200 mg / 1540.25 mm² 2 up to 340 mg / 1540.25 mm 2 is, optionally 240 mg / 1540.25 mm 2up to 300 mg / 1540.25 mm 2 . [12] Battery cell according to one of claims 1 to 11, wherein the density of the positive electrode film layer is 2.5 g / cm³ 3 up to 2.8 g / cm³ 3 is the value when the battery cell is in a state of 100% SOC. [13] Battery cell according to any one of claims 1 to 12, wherein the lithium-containing phosphate comprises at least one of the following materials: a lithium iron phosphate material and a lithium manganese iron phosphate material. [14] Battery cell according to one of claims 1 to 13, wherein the positive electrode film layer further comprises a lithium supplement, wherein the mass fraction of the lithium supplement is 0.5% to 2.5% based on the total mass of the positive electrode film layer. [15] Battery cell according to claim 14, wherein the lithium supplement comprises one or more of the following substances: lithium nickel cobalt manganese oxide, lithium phosphate, lithium hydrogen phosphate, lithium sulfate, lithium sulfite, lithium molybdate, lithium oxalate, lithium titanate, lithium tetraborate, lithium metasilicate, lithium metamanganate, lithium tartrate, trilithium citrate, lithium nickel oxide and lithium ferrite. [16] Battery cell according to any one of claims 1 to 15, wherein the positive electrode sheet and the negative electrode sheet are stacked on top of each other. [17] Battery cell according to any one of claims 1 to 16, wherein the battery cell comprises a housing body, a first end cap assembly, and a second end cap assembly, wherein the housing body, the first end cap assembly, and the second end cap assembly define a receiving cavity, wherein the first end cap assembly comprises a first end cap and at least one positive electrode terminal, wherein the positive electrode main body section is electrically connected to the positive electrode terminal via the positive electrode tab section; and / or wherein the second end cover arrangement comprises a second end cover and at least one negative electrode terminal, wherein the negative electrode main body section is electrically connected to the negative electrode terminal via the negative electrode tab section. [18] Battery cell according to claim 17, wherein the first end cap arrangement comprises the one positive electrode terminal and the one negative electrode terminal, wherein the positive electrode body section is electrically connected to the positive electrode terminal via the positive electrode tab section and the negative electrode body section is electrically connected to the negative electrode terminal via the negative electrode tab section; and / or wherein the second end cap arrangement comprises the one positive electrode terminal and the one negative electrode terminal, wherein the positive electrode body section is electrically connected to the positive electrode terminal via the positive electrode tab section and the negative electrode body section is electrically connected to the negative electrode terminal via the negative electrode tab section. [19] Battery cell according to claim 18, wherein the first end cover arrangement and the second end cover arrangement are arranged at both ends of the housing body, wherein the electrode terminals with the same polarities are arranged offset along the longitudinal direction of the battery cell on the first end cover arrangement and on the second end cover arrangement, wherein the electrode terminals with the same polarities are optionally arranged diagonally along the longitudinal direction of the battery cell. [20] Battery cell according to any one of claims 1 to 19, wherein the battery cell is configured to charge from 10% SOC to 80% SOC in a charging time of 5 minutes to 10.5 minutes. [21] Battery device comprising the battery cell according to any one of claims 1 to 20, wherein the battery device is at least one of the following: a battery module, a battery pack and an energy storage device. [22] Electrically consuming device comprising the battery cell according to any one of claims 1 to 20 or the battery device according to claim 21, wherein the battery cell or the battery device is used to provide electrical energy.

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