Lithium-ion battery cell, lithium-ion battery, and electric device

Abstract

The present application provides a lithium-ion battery cell, a lithium-ion battery, and an electric device. The lithium-ion battery cell comprises a positive electrode sheet, a negative electrode sheet, and an electrolyte, wherein the positive electrode sheet comprises a positive electrode current collector and a positive electrode active layer located on at least one surface of the positive electrode current collector, the positive electrode active material of the positive electrode active layer comprising a lithium-containing phosphate; the negative electrode sheet comprises a negative electrode current collector and a negative electrode active layer located on at least one surface of the negative electrode current collector, and the negative electrode active material of the negative electrode active layer comprises a silicon-carbon composite material, which silicon-carbon composite material comprises a silicon material and a carbon material, with the silicon material being distributed within the carbon material or the carbon material being distributed within the silicon material; and in the electrolyte, the mass percentage of fluoroethylene carbonate (FEC) in the electrolyte is less than or equal to 10%. In the lithium-ion battery cell, the lithium-containing phosphate, the silicon material, and FEC can be effectively compatible, such that the lithium-ion battery can balance both a higher energy density and better cycle performance.

Description

CROSS-REFERENCE TO RELATED APPLICATION The present application claims priority to Chinese Patent Application No. 2024110351328, filed on July 30, 2024, and entitled “LITHIUM-ION BATTERY CELL, LITHIUM-ION BATTERY, AND ELECTRICAL APPARATUS”, the disclosure of which is incorporated herein by reference in its entirety. TECHNICAL FIELD The present application relates to the technical field of batteries, and in particular, to a lithium-ion battery cell, a lithium-ion battery, and an electrical apparatus. BACKGROUND In recent years, batteries such as lithium-ion batteries have been widely used in energy storage power systems for hydroelectric power stations, thermal power stations, wind power stations, and solar power stations, as well as in various fields such as electric tools, electric bicycles, electric motorcycles, electric vehicles, military equipment, and aerospace. With the continuous expansion of the application range of batteries such as lithium-ion batteries, higher requirements have been correspondingly imposed on the performance of the batteries. In the selection of materials for batteries, lithium-containing phosphates such as lithium iron phosphate are widely used in positive electrode materials of batteries because of their advantages such as relatively low price and good cycling performance. Although these lithium-containing phosphates have the above advantages, when they are used as positive electrode materials in batteries, the energy density of the batteries is relatively low. For example, taking lithium iron phosphate as an example, its theoretical specific capacity is 170 milliampere-hours / gram (abbreviated as: mAh / g). In a conventional battery system, the specific capacity of lithium iron phosphate can approach 163 mAh / g, that is, the specific capacity of lithium iron phosphate can already be exerted to a level close to its theoretical specific capacity. However, for the battery system, the energy density of the battery still needs to be improved. SUMMARY OF THE INVENTION A first aspect of the present application provides a lithium-ion battery cell. The lithium-ion battery cell includes a positive electrode plate, a negative electrode plate, and an electrolyte solution, where the positive electrode plate includes a positive electrode current collector and a positive electrode active layer located on at least one surface of the positive electrode current collector, a positive electrode active material of the positive electrode active layer including a lithium-containing phosphate; the negative electrode plate includes a negative electrode current collector and a negative electrode active layer located on at least one surface of the negative electrode current collector, a negative electrode active material of the negative electrode active layer including a silicon-carbon composite material, where the silicon-carbon composite material includes a silicon material and a carbon material, the silicon material being distributed inside the carbon material or the carbon material being distributed inside the silicon material; and in the electrolyte solution, a mass percentage of fluoroethylene carbonate (abbreviated as: FEC) in the electrolyte solution is less than or equal to 10%. In a lithium-ion battery cell, using a silicon material in the negative electrode active material can improve the energy density of the battery cell. Since the silicon material typically has a relatively large expansion rate, a relatively large amount of FEC film-forming additive is required to improve film-forming performance so that the battery cell has relatively good cycling performance. However, FEC is relatively sensitive to moisture in the battery, and side reactions are likely to occur upon contact with water, deteriorating battery performance. The lithium-containing phosphate typically contains a relatively large amount of moisture. As such, it is difficult for the lithium-containing phosphate, the silicon material, and FEC to be effectively compatible with each other. In the lithium-ion battery cell of the present application, the carbon material in the silicon-carbon composite material can provide a certain buffering effect on the expansion of the silicon material, so that the silicon-carbon composite material has a lower expansion rate compared with conventional silicon materials, and in particular, when the silicon material is distributed inside the carbon material or the carbon material is distributed inside the silicon material in the silicon-carbon composite material, the silicon-carbon composite material has a lower expansion rate. Therefore, the silicon-carbon composite material can, on the basis of improving the energy density of the battery cell, reduce the dependency of the silicon material on FEC, so that the amount of FEC in the electrolyte solution can be reduced to below 10%. When the amount of FEC is reduced, the compatibility between FEC and the lithium-containing phosphate is improved. Therefore, in the lithium-ion battery cell of the present application, the lithium-containing phosphate, the silicon material, and the FEC can be effectively compatible, thereby allowing the lithium-ion battery including the lithium-containing phosphate to achieve both a relatively high energy density and relatively good cycling performance. In some implementations, the carbon material includes a carbon substrate, the carbon substrate including a porous carbon material and / or a fibrous carbon material. The porous carbon material and / or the fibrous carbon material can provide a relatively large number of attachment sites for the silicon material, thereby facilitating buffering of the expansion of the silicon material, and being conducive to further reducing the expansion of the silicon-carbon composite material. In some implementations, the silicon-carbon composite material includes a porous carbon material and a silicon material located in pores of the porous carbon material. The porous carbon material can provide a certain buffering for the expansion of the silicon material, reducing the overall expansion rate of the silicon-carbon composite material, and further reducing the dependency of the silicon-carbon composite material on fluoroethylene carbonate, thereby better promoting the compatibility between the silicon-carbon composite material and the lithium-containing phosphate. In some implementations, the porous carbon material includes porous hard carbon. The porous hard carbon can provide a relatively good supporting effect for the expansion of the silicon material, so that the overall expansion rate of the silicon-carbon composite material is reduced, thereby further promoting the compatibility between the silicon-carbon composite material and the lithium-containing phosphate. In addition, the porous hard carbon can also maintain relatively good particle integrity during cycling of the battery cell, with a relatively low risk of breakage and pulverization, which can promote improvement of the cycling performance of the battery cell. In some implementations, a specific surface area of the porous carbon material is 1350 square meters / gram (abbreviated as: m2 / g) to 2200 m2 / g. The specific surface area of the porous carbon material being within this range can provide suitable attachment sites for the silicon material, allowing the negative electrode plate to maintain a relatively stable structure during cycling, which is conducive to improving the cycling performance of the battery cell. In some implementations, a pore volume of the porous carbon material is 0.55 cubic centimeters / gram (abbreviated as: cm3 / g) to 1 cm3 / g, and optionally, a pore volume of micropores having a pore size less than or equal to 2 nanometers (abbreviated as: nm) in the porous carbon material is 0.4 cm3 / g to 0.8 cm3 / g. The pore volume of the porous carbon being within this range can promote uniform growth of the silicon material, allowing the distribution of the silicon material in the silicon-carbon composite material to have relatively good uniformity, and allowing the negative electrode plate to maintain a relatively stable structure during cycling, thereby being conducive to allowing the battery cell to maintain relatively good cycling performance. Further optionally, an average pore size of the pores of the porous carbon material is 1.5 nm to 5 nm. In some implementations, in the silicon-carbon composite material, a mass percentage of the silicon material in the silicon-carbon composite material is 32% to 55%. The mass percentage of the silicon material in the silicon-carbon composite material being within this range can allow the silicon-carbon composite material to have a relatively high energy density, while controlling the silicon-carbon composite material within a more suitable overall expansion rate range, thereby further reducing the dependency on fluoroethylene carbonate, and promoting the compatibility between the lithium-containing phosphate and fluoroethylene carbonate. In some implementations, the silicon material includes elemental silicon. Optionally, a crystallite size of the elemental silicon is less than or equal to 5.5 nm. The elemental silicon has a PCT / CN2025 / 083947 English translation relatively high initial efficiency, which can promote improvement of the initial efficiency of the battery cell. In some implementations, the silicon-carbon composite material further includes a carbon coating layer, the carbon coating layer coating at least a surface of the silicon material or the carbon substrate. By coating the silicon material with the carbon coating layer, contact between the electrolyte solution and the silicon material can be reduced, and exposure of new silicon interphases during cycling can be reduced, thereby further reducing the dependency of the siliconcarbon composite material on fluoroethylene carbonate, and promoting the compatibility between the silicon-carbon composite material and the lithium-containing phosphate. Optionally, the silicon material is located between the carbon substrate and the carbon coating layer. In some implementations, the silicon-carbon composite material includes a fibrous carbon material and nano-silicon particles and / or a nano-silicon layer distributed on the fibrous carbon material. In some implementations, the mass percentage of the fluoroethylene carbonate in the electrolyte solution is 1% to 10%. Using a relatively small amount of fluoroethylene carbonate can allow the lithium-containing phosphate and the silicon-carbon composite material to be relatively well compatible, and can, while fully exploiting the advantages of the lithium-containing phosphate and the silicon-carbon composite material, control the consumption of active lithium, thereby achieving a relatively superior initial coulombic efficiency. Optionally, the mass percentage of fluoroethylene carbonate in the electrolyte solution is 3% to 8%. In some implementations, the electrolyte solution includes a cyclic carbonate, and the mass percentage of the fluoroethylene carbonate in the electrolyte solution is 0. In some implementations, a volumetric capacity of the negative electrode plate is 500 milliampere-hours / cubic centimeter (abbreviated as: mAh / cm3) to 880 mAh / cm3, the volumetric capacity of the negative electrode plate being a product of a density of the negative electrode active layer and a specific capacity of the negative electrode active material. Setting the volumetric capacity of the negative electrode plate within a relatively suitable range can allow the battery cell to achieve both a relatively high energy density and a relatively high initial coulombic efficiency. In some implementations, the density of the negative electrode active layer is 1.5 grams / cubic centimeter (abbreviated as: g / cm3) to 1.75 g / cm3, optionally 1.55 g / cm3 to 1.6 g / cm3. In some implementations, a mass percentage of the silicon-carbon composite material in the negative electrode active material is 1% to 5%. In some implementations, the negative electrode active material further includes graphite, a mass ratio of the graphite to the silicon-carbon composite material being 99:1 to 95:5. In some implementations, the volumetric capacity of the negative electrode plate is 500 mAh / cm3 to 600 mAh / cm3, the electrolyte solution includes a cyclic carbonate, and the mass percentage of fluoroethylene carbonate in the electrolyte solution is 0. When the volumetric capacity of the negative electrode plate is relatively low, the density of the negative electrode plate active layer and / or the proportion of the silicon-carbon composite material in the negative electrode active material is relatively low. In this case, in the negative electrode plate, a relatively low density of the active layer can allow the negative electrode plate to have a relatively high porosity, and can allow the negative electrode plate to exhibit relatively good kinetic performance. Meanwhile, a relatively low proportion of the silicon-carbon composite material in the negative electrode active material will reduce the dependency on fluoroethylene carbonate, and even makes it possible to use no fluoroethylene carbonate. When no fluoroethylene carbonate is used, the battery cell can be allowed to have a relatively high initial coulombic efficiency. In some implementations, the density of the negative electrode active layer is 1.35 g / cm3 to 1.6 g / cm3, optionally 1.45 g / cm3 to 1.55 g / cm3. In some implementations, a mass percentage of the silicon-carbon composite material in the negative electrode active material is greater than 5% and less than or equal to 10%. In some implementations, the negative electrode active material further includes graphite, a mass ratio of the graphite to the silicon-carbon composite material being greater than or equal to 90:10 and less than 95:5. In some implementations, the volumetric capacity of the negative electrode plate is greater than 600 mAh / cm3 and less than or equal to 670 mAh / cm3, and the mass percentage of the fluoroethylene carbonate in the electrolyte solution is greater than 0 and less than or equal to 3%. In this case, the battery cell can be allowed to have a relatively high initial coulombic efficiency under a system corresponding to the configuration where the volumetric capacity of the negative electrode plate is greater than 600 mAh / cm3 and less than or equal to 670 mAh / cm3. In some implementations, the density of the negative electrode active layer is 1.3 g / cm3 to 1.6 g / cm3, optionally 1.4 g / cm3 to 1.55 g / cm3. In some implementations, a mass percentage of the silicon-carbon composite material in the negative electrode active material is greater than 10% and less than or equal to 25%. In some implementations, the negative electrode active material further includes graphite, a mass ratio of the graphite to the silicon-carbon composite material being greater than or equal to 75:25 and less than 90:10. In some implementations, the volumetric capacity of the negative electrode plate is greater than 670 mAh / cm3 and less than or equal to 880 mAh / cm3, and the mass percentage of the fluoroethylene carbonate in the electrolyte solution is greater than 3% and less than or equal to 10%. In this case, the battery cell can be allowed to have a relatively high initial coulombic efficiency under a system corresponding to the configuration where the volumetric capacity of the negative electrode plate is greater than 670 mAh / cm3 and less than or equal to 880 mAh / cm3. Optionally, the mass percentage of fluoroethylene carbonate in the electrolyte solution is 5% to 8%. In some implementations, a specific capacity of the silicon-carbon composite material is 1400 mAh / g to 2300 mAh / g. When the silicon-carbon composite material has a specific capacity of 1400 mAh / g to 2300 mAh / g, a volumetric energy density and cycle life of the battery cell can be better balanced. Optionally, the specific capacity of the silicon-carbon composite material is 1600 mAh / g to 2000 mAh / g. In some implementations, a Dv50 of the silicon-carbon composite material is 3 micrometers (abbreviated as: pm) to 15 pm. When the Dv50 of the silicon-carbon composite material is 3 pm to 15 pm, the battery cell can be allowed to have relatively good cycling performance. Optionally, the Dv50 of the silicon-carbon composite material is 6 pm to 10 pm. In some implementations, the negative electrode active material further includes graphite. Optionally, a mass percentage of the graphite in the negative electrode active material is 75% to 99%. In some implementations, a Dv50 of the graphite is 5 pm to 20 pm., optionally 10 pm to 18 pm. In some implementations, the lithium-containing phosphate includes at least one of lithium iron phosphate, a composite material of lithium iron phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon. In some implementations, a density of the positive electrode active layer is 2.3 g / cm3 to 2.9 g / cm3. The density of the positive electrode active layer being within this range can allow the positive electrode plate to have a relatively high volumetric capacity, and can also allow the positive electrode plate to maintain a relatively stable structure during a cold pressing process, reducing the risk of the positive electrode plate being damaged. Meanwhile, the density of the positive electrode active layer being within this range can allow the battery cell to have a relatively high initial coulombic efficiency. Optionally, the density of the positive electrode active layer is 2.6 g / cm3 to 2.8 g / cm3. In some implementations, a moisture content of the lithium-containing phosphate is 200 parts per million (abbreviated as: ppm) to 300 ppm. Moisture in the lithium-containing phosphate is difficult to be completely removed. During cycling of the battery cell, this moisture is likely to react with water to produce by-products and consume active lithium, leading to a decrease in the initial coulombic efficiency of the battery cell. Under normal circumstances, in a battery cell using a silicon material, FEC needs to be added to the electrolyte solution to improve the stability of a solid electrolyte interphase film (abbreviated as: SEI film). In these implementations of the present application, it is possible to use no FEC or use a small amount of FEC, which can allow the siliconcarbon composite material and the lithium-containing phosphate to be relatively well adapted to each other, and allow the battery cell to achieve both a relatively high energy density and a relatively high initial coulombic efficiency. In some implementations, a lithium salt in the electrolyte solution includes at least one of a fluorine-containing lithium phosphate salt and a fluorine-containing lithium sulfonylimide salt. In some implementations, the fluorine-containing lithium phosphate salt includes lithium hexafluorophosphate. In some implementations, the fluorine-containing lithium sulfonylimide salt includes at least one of lithium bis(fluorosulfonyl)imide and lithium bis(trifluoromethanesulfonyl)imide. A second aspect of the present application provides a lithium-ion battery. The battery includes the battery cell. A third aspect of the present application provides an electrical apparatus. The electrical apparatus includes the lithium-ion battery. BRIEF DESCRIPTION OF THE DRAWINGS In order to better describe and illustrate the embodiments or examples provided in the present application, reference may be made to one or more drawings. The additional details or examples used to describe the drawings should not be considered as limiting the scope of the disclosed applications, currently described embodiments or examples, and any one of currently understood preferred embodiments of these applications. Moreover, in all of the figures, identical parts are represented by identical reference numerals. In the accompanying drawings: FIG. 1 is a schematic diagram of a silicon-carbon composite material in an implementation of the present application. FIG. 2 is a schematic diagram of a silicon-carbon composite material in another implementation of the present application. FIG. 3 is a schematic diagram of a battery cell according to an implementation of the present application. FIG. 4 is an exploded view of the battery cell according to the implementation of the present application shown in FIG. 3. FIG. 5 is a schematic diagram of an electrical apparatus using the battery cell as a power source according to an implementation of the present application. Description of Reference Numerals: PCT / CN2025 / 083947 English translation 1: battery cell; 11: case; 12: electrode assembly; 13: cover plate; 2: electrical apparatus; 3: silicon-carbon composite material; 31: porous carbon material; 311: pore; 32: silicon material; 4: silicon-carbon composite material; 41: fibrous carbon material; 42: nano-silicon particle; 43: nanosilicon layer. DETAILED DESCRIPTION To facilitate understanding of the present application, the present application will be described more comprehensively below with reference to the relevant drawings. Preferred embodiments of the present application are shown in the accompanying drawings. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided for the purpose of more thoroughly and completely understanding the content disclosed by the present application. Unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the field to which the present application belongs. Herein, the terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The term “and / or” used herein includes any and all combinations of one or more relevant items listed. The “ranges” disclosed in the present application can be defined in the form of lower and upper limits. A given range is defined by selecting a lower limit and an upper limit, and the selected lower and upper limits define the boundaries of the particular range. The range defined in this way may include or may not include end values, and any end value may be included or excluded independently and may be arbitrarily combined, that is, any lower limit may be combined with any upper limit to form a range. For example, if the ranges 60-120 and 80-110 are listed for specific parameters, it is understood that the ranges 60-110 and 80-120 are also expected. In addition, if the listed minimum range values are 1 and 2 and if the maximum range values of 3, 4, and 5 are also listed, the following ranges can all be expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In the present application, unless otherwise specified, the numerical range “a-b” represents an abbreviated representation of any combination of real numbers between a and b, where a and b are both real numbers. For example, the numerical range “0-5” indicates that all real numbers between “0-5” have been listed herein, and “0-5” is only an abbreviated representation of these numerical combinations. In addition, when a parameter is expressed as an integer > 2, it is equivalent to listing the parameter as, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc. For example, when a parameter is expressed as an integer selected from “2-10”, it is equivalent to listing an integer of 2, 3, 4, 5, 6, 7, 8, 9, and 10. PCT / CN2025 / 083947 English translation The “plurality” involved in the present application, unless otherwise specified, refers to a number greater than 2 or equal to 2. For example, the “one or more” means one or greater than or equal to two. Unless otherwise particularly stated, all embodiments and optional embodiments of the present application may be combined with each other to form new technical solutions. Reference herein to “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one example or embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments. The “embodiment” mentioned herein is understood similarly. It should be understood by those skilled in the art that in the method of each embodiment or example, the writing order of various steps does not imply a strict performing order to constitute any limitation on the implementation process. The detailed order of performing the various steps should be determined by its function and possible internal logic. Unless otherwise specified, all steps in the present application may be performed sequentially or may be performed randomly. For example, the method comprises steps (a) and (b), which means that the method may comprise steps (a) and (b) performed in order, or may comprise steps (b) and (a) performed in order. For example, the reference to the method may further comprise step (c), which means that step (c) may be added to the method in any sequence, for example, the method may comprise steps (a), (b) and (c), or may comprise steps (a), (c) and (b), or may comprise steps (c), (a) and (b), and so on. In the present application, in open-ended technical features or technical solutions described with the wordings such as “contain,” “include,” or “comprise,” unless otherwise stated, additional members other than the enumerated members are not excluded, which may be regarded as providing both close-ended features or solutions consisting of the enumerated members and open-ended features or solutions including additional members in addition to the enumerated members. For example, A comprises a1, a2, and a3, and unless otherwise stated, may further comprise other members or may not comprise additional members, which may be regarded as providing both the feature or solution that “A consists of a1, a2, and a3” and the feature or solution that “A not only comprises a1, a2, and a3, but also comprises other members.” In the present application, unless otherwise stated, “A, such as B” means that B is a nonlimiting example of A and it is to be understood that A is not limited to B. In the present application, the “optionally” and “optional” mean dispensable, that is, they mean any one selected from two parallel solutions of “presence” or “absence”. If there are a plurality of PCT / CN2025 / 083947 English translation instances of “optional” in a technical solution, unless otherwise specified, and there are no contradictions or interdependencies, each “optional” is independent. An implementation of the present application provides a lithium-ion battery cell. The battery cell includes a positive electrode plate, a negative electrode plate, and an electrolyte solution. The positive electrode plate includes a positive electrode current collector and a positive electrode active layer located on at least one surface of the positive electrode current collector, a positive electrode active material of the positive electrode active layer including a lithium-containing phosphate. The negative electrode plate includes a negative electrode current collector and a negative electrode active layer located on at least one surface of the negative electrode current collector, a negative electrode active material of the negative electrode active layer including a silicon-carbon composite material. The silicon-carbon composite material includes a silicon material and a carbon material, the silicon material being distributed inside the carbon material or the carbon material being distributed inside the silicon material; and in the electrolyte solution, a mass percentage of fluoroethylene carbonate in the electrolyte solution is less than or equal to 10%. The silicon material has a relatively high specific capacity. Therefore, using the silicon material in the negative electrode active material can improve the energy density of the battery cell. Since the silicon material typically has a relatively large expansion rate, a relatively large amount of FEC film-forming additive is required to improve film-forming performance so that the battery cell has relatively good cycling performance. However, FEC is relatively sensitive to moisture in the battery, and side reactions are likely to occur upon contact with water, deteriorating battery performance. The lithium-containing phosphate typically contains a relatively large amount of moisture. As such, it is difficult for the lithium-containing phosphate, the silicon material, and FEC to be effectively compatible with each other. In this implementation, the carbon material in the silicon-carbon composite material can provide a certain buffering effect on the expansion of the silicon material, so that the silicon-carbon composite material has a lower expansion rate compared with conventional silicon materials, and in particular, when the silicon material is distributed inside the carbon material or the carbon material is distributed inside the silicon material in the siliconcarbon composite material, the silicon-carbon composite material has a lower expansion rate. Therefore, the silicon-carbon composite material can, on the basis of improving the energy density of the battery cell, reduce the dependency of the silicon material on FEC, so that the amount of FEC in the electrolyte solution can be reduced to below 10%. When the amount of FEC is reduced, the compatibility between FEC and the lithium-containing phosphate is improved. Therefore, in the lithium-ion battery cell of the present application, the lithium-containing phosphate, the silicon material, and the FEC can be effectively compatible, thereby allowing the lithium-ion battery PCT / CN2025 / 083947 English translation including the lithium-containing phosphate to achieve both a relatively high energy density and relatively good cycling performance. Further, in this implementation, the amount of FEC used is small, and the amount of active lithium consumed due to generation of by-products through a reaction between FEC and water is relatively small, thereby allowing the battery cell to maintain a relatively high initial coulombic efficiency. It can be understood that, in this implementation, the silicon material is distributed inside the carbon material or the carbon material is distributed inside the silicon material, where the “inside” may be in forms such as inside pores of the material, surface folds, recesses, or inside a solid material. Optionally, in the electrolyte solution, the mass percentage of FEC in the electrolyte solution may be 0, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, and any value within a range constituted by any two of the aforementioned numerical values. In the electrolyte solution, selecting the mass percentage of FEC in the electrolyte solution within the range of less than or equal to 10% can allow the battery cell to achieve both relatively good negative-electrode film formation and relatively low side reactions, promoting improvement of the energy density of the battery cell and maintenance of a relatively high initial efficiency. In some implementations, the carbon material includes a carbon substrate, the carbon substrate including a porous carbon material and / or a fibrous carbon material. The porous carbon material and / or the fibrous carbon material can provide a relatively large number of attachment sites for the silicon material, thereby facilitating buffering of the expansion of the silicon material, and being conducive to further reducing the expansion of the silicon-carbon composite material. As an example, the fibrous carbon material may be in the form of a wire, a tube, a rod, or the like. Specifically, the fibrous carbon material may be a carbon nanotube, a carbon nanofiber, or a composite structure formed by any combination thereof. Referring to FIG. 1, in some implementations, the silicon-carbon composite material 3 includes a porous carbon material 31 and a silicon material 32 located in pores 311 of the porous carbon material 31. The porous carbon material can provide a certain buffering for the expansion of the silicon material, reducing the overall expansion rate of the silicon-carbon composite material, and further reducing the dependency of the silicon-carbon composite material on FEC, thereby better promoting the compatibility between the silicon-carbon composite material and the lithium-containing phosphate. At the same time, the reduction of the overall expansion rate of the siliconcarbon composite material can reduce the expansion of the negative electrode plate during cycling, allowing the negative electrode plate to maintain a relatively stable structure during cycling, PCT / CN2025 / 083947 English translation thereby being conducive to allowing the battery cell to maintain relatively good cycling performance. Optionally, the porous carbon material includes porous hard carbon. The porous hard carbon can provide a relatively good supporting effect for the expansion of the silicon material, so that the overall expansion rate of the silicon-carbon composite material is reduced, thereby further promoting the compatibility between the silicon-carbon composite material and the lithium-containing phosphate. In addition, the porous hard carbon can also maintain relatively good particle integrity during cycling of the battery cell, with a relatively low risk of breakage and pulverization, which can promote improvement of the cycling performance of the battery cell. In some implementations, a specific surface area of the porous carbon material is 1350 m2 / g to 2200 m2 / g. The specific surface area of the porous carbon material being within this range can provide suitable attachment sites for the silicon material, allowing the negative electrode plate to maintain a relatively stable structure during cycling, which is conducive to improving the cycling performance of the battery cell. Optionally, the specific surface area of the porous carbon material may be 1350 m2 / g, 1400 m2 / g, 1500 m2 / g, 1600 m2 / g, 1700 m2 / g, 1800 m2 / g, 1900 m2 / g, 2000 m2 / g, 2100 m2 / g, 2200 m2 / g, and any value within a range constituted by any two of the aforementioned numerical values. In some implementations, a pore volume of the porous carbon material is 0.55 cm3 / g to 1 cm3 / g. Optionally, a pore volume of micropores having a pore size less than or equal to 2 nm in the porous carbon material is 0.4 cm3 / g to 0.8 cm3 / g. The pore volume of the porous carbon being within this range can promote uniform growth of the silicon material, allowing the distribution of the silicon material in the silicon-carbon composite material to have relatively good uniformity, and allowing the negative electrode plate to maintain a relatively stable structure during cycling, thereby being conducive to allowing the battery cell to maintain relatively good cycling performance. Optionally, the pore volume of the porous carbon material may be 0.55 cm3 / g, 0.6 cm3 / g, 0.65 cm3 / g, 0.7 cm3 / g, 0.75 cm3 / g, 0.8 cm3 / g, 0.85 cm3 / g, 0.9 cm3 / g, 0.95 cm3 / g, 1 cm3 / g, and any value within a range constituted by any two of the aforementioned numerical values. Further optionally, the pore volume of micropores having a pore size less than or equal to 2 nm in the porous carbon material may be 0.4 cm3 / g, 0.45 cm3 / g, 0.5 cm3 / g, 0.55 cm3 / g, 0.6 cm3 / g, 0.65 cm3 / g, 0.7 cm3 / g, 0.75 cm3 / g, 0.8 cm3 / g, and any value within a range constituted by any two of the aforementioned numerical values. Further optionally, an average pore size of the pores of the porous carbon material is 1.5 nm to 5 nm. Optionally, the average pore size of the pores of the porous carbon material may be 1.5 nm, 2 nm, 2.5 nm, 3 nm, 3.5 nm, 4 nm, 4.5 nm, 5 nm, and any value within a range constituted by any two of the aforementioned numerical values. PCT / CN2025 / 083947 English translation In some implementations, the silicon-carbon composite material includes a carbon nanofiber and a silicon material located on the carbon nanofiber. Further, the silicon-carbon composite material includes a carbon nanotube. The addition of the carbon nanotube can improve the stability of the structure of the silicon-carbon composite material. In some implementations, in the silicon-carbon composite material, a mass percentage of the silicon material in the silicon-carbon composite material is 32% to 55%. The mass percentage of the silicon material in the silicon-carbon composite material being within this range can allow the silicon-carbon composite material to have a relatively high energy density, while controlling the silicon-carbon composite material within a more suitable overall expansion rate range, thereby further reducing the dependency on FEC, and promoting the compatibility between the lithium-containing phosphate and FEC. Optionally, the mass percentage of the silicon material in the silicon-carbon composite material may be 32%, 35%, 40%, 45%, 50%, 55%, and any value within a range constituted by any two of the aforementioned numerical values. In some implementations, the silicon material includes elemental silicon. The elemental silicon has a relatively high initial efficiency, which can promote improvement of the initial efficiency of the battery cell. Optionally, the silicon material includes nano elemental silicon. Further optionally, a crystallite size of the nano elemental silicon is less than or equal to 5.5 nm. Further, the silicon-carbon composite material further includes a carbon coating layer, the carbon coating layer coating at least a surface of the silicon material or the carbon substrate. By coating the silicon material with the carbon coating layer, contact between the electrolyte solution and the silicon material can be reduced, and exposure of new silicon interphases during cycling can be reduced, thereby further reducing the dependency of the silicon-carbon composite material on FEC, and promoting the compatibility between the silicon-carbon composite material and the lithium-containing phosphate. Optionally, the silicon material is located between the carbon substrate and the carbon coating layer. In some implementations, the silicon-carbon composite material may be prepared by depositing the silicon material in the pores of the porous carbon material by means of vapor deposition. Optionally, a preparation method for the silicon-carbon composite material includes the following steps: under an argon atmosphere, heating the porous carbon material in a reactor to 500 degrees Celsius (abbreviated as: °C), and maintaining the temperature for 2 hours (abbreviated as: h), so as to desorb air adsorbed in the porous carbon. Introducing a mixed gas of silane and argon into the reactor at a gas flow rate of 4 liters / minute (abbreviated as: L / min), where a volume ratio of silane to argon is 1:4, then heating the reactor to a temperature of 600°C, and introducing a mixed gas of acetylene and argon at a gas flow rate of 3 L / min, where a volume ratio of acetylene to argon is 1:4, so as to perform a coating treatment on silicon-carbon particles. In some PCT / CN2025 / 083947 English translation implementations, a first-cycle delithiation capacity of the prepared silicon-carbon composite material is 1400 mAh / g to 2300 mAh / g. Referring to FIG. 2, in some implementations, the silicon-carbon composite material 4 includes a fibrous carbon material 41 and nano-silicon particles 42 and / or a nano-silicon layer 43 distributed on the fibrous carbon material 41. In some implementations, the mass percentage of the fluoroethylene carbonate in the electrolyte solution is 1% to 10%. Using a relatively small amount of fluoroethylene carbonate can allow the lithium-containing phosphate and the silicon-carbon composite material to be relatively well compatible, and can, while fully exploiting the advantages of the lithium-containing phosphate and the silicon-carbon composite material, control the consumption of active lithium, thereby achieving a relatively superior initial coulombic efficiency. Optionally, the mass percentage of the fluoroethylene carbonate in the electrolyte solution is 3% to 8%. Optionally, when the mass percentage of fluoroethylene carbonate in the electrolyte solution is 1% to 10%, the electrolyte solution may further include a solvent such as a cyclic carbonate and a chain carbonate. In some implementations, the electrolyte solution includes a cyclic carbonate, and the mass percentage of the fluoroethylene carbonate in the electrolyte solution is 0. In some implementations, a volumetric capacity of the negative electrode plate is 500 mAh / cm3 to 880 mAh / cm3, the volumetric capacity of the negative electrode plate being a product of a density of the negative electrode plate active layer and a specific capacity of the negative electrode active material. For a battery cell, an increase in the volumetric capacity of the negative electrode plate can improve the energy density of the battery cell. However, limited by the composition of the negative electrode plate, the improvement of the volumetric capacity of the negative electrode plate is often subject to certain constraints. For example, in the negative electrode plate, the volumetric capacity can be improved by increasing the density of the negative electrode plate active layer and increasing the proportion of the silicon-carbon composite material in the negative electrode active material. When the density of the negative electrode plate active layer increases, the degree of compression on the silicon-carbon composite material will increase accordingly, and the risk of breakage of the silicon-carbon composite material increases, resulting in an increase in the number of reaction sites and thus increasing film formation consumption, and the porosity of the negative electrode plate will also be reduced, which may lead to a reduction in the initial coulombic efficiency of the battery cell. Therefore, setting the volumetric capacity of the negative electrode plate within a relatively suitable range can allow the battery cell to achieve both a relatively high energy density and a relatively high initial coulombic efficiency. Optionally, the volumetric capacity of the negative electrode plate is 500 mAh / cm3 to 880 mAh / cm3. Further optionally, the volumetric capacity of the negative electrode plate may be 500 mAh / cm3, 550 mAh / cm3, 600 mAh / cm3, 650 mAh / cm3, 700 mAh / cm3, 750 mAh / cm3, 800 mAh / cm3, 850 mAh / cm3, 880 mAh / cm3, and any value within a range constituted by any two of the aforementioned numerical values. Still further optionally, the volumetric capacity of the negative electrode plate is 650 mAh / cm3 to 750 mAh / cm3, and within this volumetric capacity range, the battery cell can exhibit better overall performance in terms of initial coulombic efficiency and energy density. In some implementations, the volumetric capacity of the negative electrode plate can be adjusted by means of a suitable density of the active layer and a suitable proportion of the siliconcarbon composite material. Optionally, the density of the negative electrode plate active layer is 1.5 g / cm3 to 1.75 g / cm3. For example, the density of the negative electrode plate active layer may be 1.5 g / cm3, 1.55 g / cm3, 1.6 g / cm3, 1.65 g / cm3, 1.7 g / cm3, 1.75 g / cm3, and any value within a range constituted by any two of the aforementioned numerical values. Further optionally, the density of the negative electrode plate active layer is 1.55 g / cm3 to 1.6 g / cm3. Optionally, a mass percentage of the silicon-carbon composite material in the negative electrode active material is 1% to 5%. For example, the mass percentage of the silicon-carbon composite material in the negative electrode active material may be 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, and any value within a range constituted by any two of the aforementioned numerical values. Further optionally, the negative electrode active material further includes graphite, a mass ratio of the graphite to the silicon-carbon composite material being 99:1 to 95:5. For example, the mass ratio of the graphite to the silicon-carbon composite material may be 99:1, 98:2, 97:3, 96:4, 95:5, and any ratio within a range constituted by any two of the aforementioned ratios. In some implementations, the volumetric capacity of the negative electrode plate is 500 mAh / cm3 to 600 mAh / cm3, the electrolyte solution includes a cyclic carbonate, and the mass percentage of fluoroethylene carbonate in the electrolyte solution is 0. When the volumetric capacity of the negative electrode plate is relatively low, the density of the negative electrode plate active layer and / or the proportion of the silicon-carbon composite material in the negative electrode active material is relatively low. In this case, in the negative electrode plate, a relatively low density of the active layer can allow the negative electrode plate to have a relatively high porosity, and can allow the negative electrode plate to exhibit relatively good kinetic performance. Meanwhile, a relatively low proportion of the silicon-carbon composite material in the negative electrode active material will reduce the dependency on fluoroethylene carbonate, and even makes it possible to use no fluoroethylene carbonate. When no fluoroethylene carbonate is used, the battery cell can be allowed to have a relatively high initial coulombic efficiency. In the case where the proportion of the silicon-carbon composite material in the negative electrode active material is relatively small, the negative electrode plate can be designed with a relatively high compaction density to allow the battery cell to have a relatively high energy density under a system corresponding to the configuration where the volumetric capacity of the negative electrode plate is 500 mAh / cm3 to 600 mAh / cm3. For example, when the mass percentage of the silicon-carbon composite material in the negative electrode active material is 1%, the density of the negative electrode plate active layer can be set to a relatively high value of 1.75 g / cm3. When the mass percentage of the silicon-carbon composite material in the negative electrode active material is 5%, the density of the negative electrode plate active layer can be set to a relatively low value of 1.5 g / cm3. In some implementations, the density of the negative electrode plate active layer is 1.35 g / cm3 to 1.6 g / cm3. For example, the density of the negative electrode plate active layer may be 1.35 g / cm3, 1.4 g / cm3, 1.45 g / cm3, 1.5 g / cm3, 1.55 g / cm3, 1.6 g / cm3, and any value within a range constituted by any two of the aforementioned numerical values. Further optionally, the density of the negative electrode plate active layer is 1.45 g / cm3 to 1.55 g / cm3. Optionally, the mass percentage of the silicon-carbon composite material in the negative electrode active material is greater than 5% and less than or equal to 10%. For example, the mass percentage of the siliconcarbon composite material in the negative electrode active material may be 5.1%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, and any value within a range constituted by any two of the aforementioned numerical values. Further optionally, the mass ratio of the graphite to the siliconcarbon composite material is greater than or equal to 90:10 and less than 95:5. For example, the mass ratio of the graphite to the silicon-carbon composite material may be 90:10, 91:9, 92:8, 93:7, 94:6, and any ratio within a range constituted by any two of the aforementioned ratios. In some implementations, the volumetric capacity of the negative electrode plate is greater than 600 mAh / cm3 and less than or equal to 670 mAh / cm3, and the mass percentage of the fluoroethylene carbonate in the electrolyte solution is greater than 0 and less than or equal to 3%. In this case, the battery cell can be allowed to have a relatively high initial coulombic efficiency under a system corresponding to the configuration where the volumetric capacity of the negative electrode plate is greater than 600 mAh / cm3 and less than or equal to 670 mAh / cm3. It can be understood that, under the system corresponding to the configuration where the volumetric capacity of the negative electrode plate is greater than 600 mAh / cm3 and less than or equal to 670 mAh / cm3, when the mass percentage of the silicon-carbon composite material in the negative electrode active material is slightly greater than 5%, the density of the negative electrode plate active layer can be set to a relatively high value of 1.6 g / cm3. When the mass percentage of the silicon-carbon composite material in the negative electrode active material is 10%, the density of the negative electrode plate active layer can be set to a relatively low value of 1.35 g / cm3. In some implementations, the density of the negative electrode plate active layer is 1.3 g / cm3 to 1.6 g / cm3. For example, the density of the negative electrode plate active layer may be 1.3 g / cm3, 1.35 g / cm3, 1.4 g / cm3, 1.45 g / cm3, 1.5 g / cm3, 1.55 g / cm3, 1.6 g / cm3, and any value within a range constituted by any two of the aforementioned numerical values. Optionally, it is 1.4 g / cm3 to 1.55 g / cm3. Optionally, the mass percentage of the silicon-carbon composite material in the negative electrode active material is greater than 10% and less than or equal to 25%. For example, the mass percentage of the silicon-carbon composite material in the negative electrode active material may be 11%, 12%, 15%, 18%, 20%, 22%, 25%, and any value within a range constituted by any two of the aforementioned numerical values. Further optionally, the negative electrode active material further includes graphite, a mass ratio of the graphite to the silicon-carbon composite material is greater than or equal to 75:25 and less than 90:10. For example, the mass ratio of the graphite to the silicon-carbon composite material may be 80:20, 83:17, 85:15, 88:12, and any ratio within a range constituted by any two of the aforementioned ratios. In some implementations, the volumetric capacity of the negative electrode plate is greater than 670 mAh / cm3 and less than or equal to 880 mAh / cm3, and the mass percentage of the fluoroethylene carbonate in the electrolyte solution is greater than 3% and less than or equal to 10%. In this case, the battery cell can be allowed to have a relatively high initial coulombic efficiency under a system corresponding to the configuration where the volumetric capacity of the negative electrode plate is greater than 670 mAh / cm3 and less than or equal to 880 mAh / cm3. Optionally, the mass percentage of fluoroethylene carbonate in the electrolyte solution is 5% to 8%. It can be understood that, under the system corresponding to the configuration where the volumetric capacity of the negative electrode plate is greater than 670 mAh / cm3 and less than or equal to 880 mAh / cm3, when the mass percentage of the silicon-carbon composite material in the negative electrode active material is slightly greater than 10%, the density of the negative electrode plate active layer can be set to a relatively high value of 1.6 g / cm3. When the mass percentage of the silicon-carbon composite material in the negative electrode active material is 25%, the density of the negative electrode plate active layer can be set to a relatively low value of 1.3 g / cm3. In some implementations, a specific capacity of the silicon-carbon composite material is 1400 mAh / g to 2300 mAh / g. The specific capacity of the silicon-carbon composite material is related to the content of the silicon material in the pores of the porous carbon. When the silicon-carbon composite material has a specific capacity of 1400 mAh / g to 2300 mAh / g, a volumetric energy density and cycle life of the battery cell can be better balanced. Optionally, the specific capacity of the silicon-carbon composite material may be 1400 mAh / g, 1500 mAh / g, 1600 mAh / g, 1700 mAh / g, 1800 mAh / g, 1900 mAh / g, 2000 mAh / g, 2100 mAh / g, 2200 mAh / g, 2300 mAh / g, and any PCT / CN2025 / 083947 English translation value within a range constituted by any two of the aforementioned numerical values. Further optionally, the specific capacity of the silicon-carbon composite material is 1600 mAh / g to 2000 mAh / g. In some implementations, a Dv50 of the silicon-carbon composite material is 3 pm to 15 pm. When the Dv50 of the silicon-carbon composite material is 3 pm to 15 pm, the battery cell can be allowed to have relatively good cycling performance. Optionally, the Dv50 of the silicon-carbon composite material may be 3 pm, 4 pm, 5 pm, 6 pm, 7 pm, 8 pm, 9 pm, 10 pm, 11 pm, 12 pm, 13 pm, 14 pm, 15 pm, and any value within a range constituted by any two of the aforementioned numerical values. Further optionally, the Dv50 of the silicon-carbon composite material is 6 pm to 10 pm. In some implementations, the negative electrode active material further includes graphite. Optionally, a mass percentage of the graphite in the negative electrode active material is 75% to 99%. Optionally, in the negative electrode active material, when the mass percentage of the siliconcarbon composite material in the negative electrode active material is 1% to 5%, the mass percentage of the graphite in the negative electrode active material is 95% to 99%. When the mass percentage of the silicon-carbon composite material in the negative electrode active material is 5% to 10%, the mass percentage of the graphite in the negative electrode active material is 90% to 95%. When the mass percentage of the silicon-carbon composite material in the negative electrode active material is 10% to 25%, the mass percentage of the graphite in the negative electrode active material is 75% to 90%. In some implementations, a Dv50 of the graphite is 5 pm to 20 pm. Optionally, the Dv50 of the graphite may be 5 pm, 6 pm, 7 pm, 8 pm, 9 pm, 10 pm, 11 pm, 12 pm, 13 pm, 14 pm, 15 pm, 16 pm, 17 pm, 18 pm, 19 pm, 20 pm, and any value within a range constituted by any two of the aforementioned numerical values. Further optionally, the Dv50 of the graphite is 10 pm to 18 pm. In the present application, Dv50 refers to: in a volume cumulative distribution curve, the particle size corresponding to the case where the cumulative particle size distribution number of the particles reaches 50%, and its physical meaning is that particles having a particle size smaller than or greater than it account for 50%. As an example, Dv50 can be obtained based on a particle size distribution curve obtained by using a laser diffraction particle size distribution measuring instrument Mastersizer 3000 with reference to a test method in GB / T 19077-2016. In some implementations, the lithium-containing phosphate includes at least one of lithium iron phosphate, a composite material of lithium iron phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon. Optionally, the lithium-containing phosphate includes an olivine-structured lithium-containing phosphate. In some implementations, a density of the positive electrode active layer is 2.3 g / cm3 to 2.9 g / cm3. The density of the positive electrode active layer being within this range can allow the positive electrode plate to have a relatively high volumetric capacity, and can also allow the positive electrode plate to maintain a relatively stable structure during a cold pressing process, reducing the risk of the positive electrode plate being damaged. Meanwhile, the density of the positive electrode active layer being within this range can allow the battery cell to have a relatively high initial coulombic efficiency. Optionally, the density of the positive electrode active layer may be 2.3 g / cm3, 2.4 g / cm3, 2.5 g / cm3, 2.6 g / cm3, 2.7 g / cm3, 2.8 g / cm3, 2.9 g / cm3, and any value within a range constituted by any two of the aforementioned numerical values. Further optionally, the density of the positive electrode active layer is 2.6 g / cm3 to 2.8 g / cm3. In some implementations, a moisture content of the lithium-containing phosphate is 200 ppm to 300 ppm. Moisture in the lithium-containing phosphate is difficult to be completely removed. During cycling of the battery cell, this moisture is likely to react with water to produce by-products and consume active lithium, leading to a decrease in the initial coulombic efficiency of the battery cell. Under normal circumstances, in a battery cell using a silicon material, FEC needs to be added to the electrolyte solution to improve the stability of a solid electrolyte interphase film. In these implementations of the present application, it is possible to use no FEC or use a small amount of FEC, which can allow the silicon-carbon composite material and the lithium-containing phosphate to be relatively well adapted to each other, and allow the battery cell to achieve both a relatively high energy density and a relatively high initial coulombic efficiency. In some implementations, a lithium salt in the electrolyte solution includes at least one of a fluorine-containing lithium phosphate salt and a fluorine-containing lithium sulfonylimide salt. Optionally, the fluorinecontaining lithium phosphate salt includes lithium hexafluorophosphate. The fluorine-containing lithium sulfonylimide salt includes at least one of lithium bis(fluorosulfonyl)imide and lithium bis(trifluoromethanesulfonyl)imide. Another implementation of the present application provides a lithium-ion battery. The battery includes the aforementioned lithium-ion battery cell. Still another implementation of the present application provides an electrical apparatus. The electrical apparatus includes the aforementioned lithium-ion battery. Hereinafter, the battery cell, the battery, and the electrical apparatus of the present application will be described with appropriate reference to the accompanying drawings. Generally, a battery cell includes a positive electrode plate, a negative electrode plate, an electrolyte, and a separator. In a charge-discharge process of a battery, active ions reciprocally intercalate and deintercalate between a positive electrode plate and a negative electrode plate. The electrolyte plays a role in conducting ions between the positive electrode plate and negative PCT / CN2025 / 083947 English translation electrode plate. The separator is arranged between the positive electrode plate and the negative electrode plate and mainly serves to prevent a short circuit between the positive and negative electrodes while allowing ions to pass through. Positive electrode plate The positive electrode plate includes a positive electrode current collector and a positive electrode active layer disposed on at least one surface of the positive electrode current collector, the positive electrode active layer including a positive electrode active material. As a non-limiting example, the positive electrode current collector has two opposing surfaces in its own thickness direction, and the positive electrode active layer is disposed on either one or both of the two opposing surfaces of the positive electrode current collector. In some implementations, the positive electrode current collector may employ a metal foil or a composite current collector. For example, as the metal foil, an aluminum foil can be used. The composite current collector may include a high molecular material substrate layer and a metal layer formed on at least one surface of the high molecular material substrate layer. The composite current collector may be obtained by forming a metal material on a high molecular material substrate. In the positive electrode current collector, non-limiting examples of the metal material may include one or more of aluminum, an aluminum alloy, nickel, a nickel alloy, titanium, a titanium alloy, silver, and a silver alloy. In the positive electrode current collector, non-limiting examples of the polymer material substrate may include one or more of substrates such as polypropylene (abbreviated as: PP), polyethylene terephthalate (abbreviated as: PET), polybutylene terephthalate (abbreviated as: PBT), polystyrene (abbreviated as: PS), polyethylene (abbreviated as: PE), etc. In some of the embodiments, the lithium-containing phosphate may also include one or more of lithium manganese phosphate and a composite material of lithium manganese phosphate and carbon. Optionally, the positive electrode active material may also include a positive electrode active material for batteries known in the art. As a non-limiting example, the positive electrode active material may also include one or more of the following materials: lithium transition metal oxides and respective modified compounds thereof. However, the present application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone as one kind, or may be used in combination of two or more kinds. Here, examples of the lithium transition metal oxides may include, but are not limited to, one or more of lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, and modified compounds thereof, etc. Non-limiting examples of the lithium cobalt oxide may include LiCoO2; non-limiting examples of the lithium nickel oxide may include LiNiO2; non-limiting examples of the lithium manganese oxide may include LiMnO2, LiMn2O4, etc.; non-limiting examples of the lithium nickel cobalt manganese oxide may include LiNi1 / 3Co1 / 3Mn1 / 3O2 (abbreviated as: NCM333), LiNi0.5Co0.2Mn0.3O2 (abbreviated as: NCM523), LiNi0.5Co0.25Mn0.25O2 (abbreviated as: NCM211), LiNi0.6Co0.2Mn0.2O2 (abbreviated as: NCM622), LiNi0.8Co0.1Mn0.1O2 (abbreviated as: NCM811), etc. Non-limiting examples of the lithium nickel cobalt aluminum oxide may include LiNi0.8Co0.15Al0.05O2. In some of the embodiments, the positive electrode active layer may optionally include a binder. As a non-limiting example, the binder may include one or more of polyvinylidene fluoride (abbreviated as: PVDF), polytetrafluoroethylene (abbreviated as: PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorinecontaining acrylate resin. In some of the embodiments, the positive electrode active layer may optionally include a conductive agent. As a non-limiting example, the conductive agent may comprise one or more of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers. In some of the embodiments, the positive electrode plate may be prepared by the following method: dispersing the aforementioned components for preparing the positive electrode plate, for example, the positive electrode active material, the conductive agent, the binder, and any other components, in a solvent to form a positive electrode slurry; coating the positive electrode slurry on at least one side surface of the positive electrode current collector, and after processes such as drying and cold pressing, the positive electrode plate can be obtained. The kind of the solvent may be selected from, but is not limited to, any one in the aforementioned implementations, for example, N-methylpyrrolidone (abbreviated as: NMP). The surface of the positive electrode current collector on which the positive electrode slurry is coated may be a single surface of the positive electrode current collector, or may be both surfaces of the positive electrode current collector. A solid content of the positive electrode slurry may be 40 wt% (abbreviated as: wt%) to 80 wt%. A viscosity of the positive electrode slurry at room temperature may be adjusted to 5000 millipascabseconds (abbreviated as: mPa^s) to 25000 mPa^s. Negative electrode plate The negative electrode plate includes a negative electrode current collector and a negative electrode active layer disposed on at least one surface of the negative electrode current collector, the negative electrode active layer including a negative electrode active material. PCT / CN2025 / 083947 English translation As a non-limiting example, the negative electrode current collector has two opposing surfaces in its own thickness direction, and the negative electrode active layer is disposed on either one or both of the two opposing surfaces of the negative electrode current collector. In some of the embodiments, the negative electrode current collector may employ a metal foil or a composite current collector. For example, a copper foil may be used as the metal foil. The composite current collector may include a high molecular material substrate layer and a metal layer formed on at least one surface of the high molecular material substrate. The composite current collector may be obtained by forming a metal material on a high molecular material substrate. In the negative electrode current collector, non-limiting examples of the metal material may include one or more of copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc. In the negative electrode current collector, non-limiting examples of the polymer material substrate may include one or more of substrates such as polypropylene (abbreviated as: PP), polyethylene terephthalate (abbreviated as: PET), polybutylene terephthalate (abbreviated as: PBT), polystyrene (abbreviated as: PS), polyethylene (abbreviated as: PE), etc. In some of the embodiments, the negative electrode active material includes the silicon-carbon composite material and graphite. Optionally, the graphite includes one or more of artificial graphite and natural graphite. Further optionally, the negative electrode active material may also employ a negative electrode active material for batteries known in the art. As a non-limiting example, the negative electrode active material may include one or more of the following materials: soft carbon, hard carbon, a tin-based material, lithium titanate, etc. The tin-based material may include one or more of elemental tin, a tin-oxygen compound, and a tin alloy. However, the present application is not limited to these materials, and other conventional materials that may be used as negative electrode active materials for batteries may also be used. One of these negative active materials may be used alone, or two or more of these positive active materials may be used in combination. In some of the embodiments, the negative electrode active layer may optionally include a binder. The binder may include one or more of styrene-butadiene rubber (abbreviated as: SBR), polyacrylic acid (abbreviated as: PAA), sodium polyacrylate (abbreviated as: PAAS), polyacrylamide (abbreviated as: PAM), polyvinyl alcohol (abbreviated as: PVA), sodium alginate (abbreviated as: SA), polymethacrylic acid (abbreviated as: PMAA), and carboxymethyl chitosan (abbreviated as: CMCS). In some of the embodiments, the negative electrode active layer may optionally include a conductive agent. The conductive agent may include one or more of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers. PCT / CN2025 / 083947 English translation In some of the embodiments, the negative electrode active layer may optionally include other auxiliaries, for example, a thickener, etc. The thickener may include sodium carboxymethyl cellulose (abbreviated as: CMC-Na). In some of the embodiments, the negative electrode plate may be prepared by the following method: dispersing the aforementioned components for preparing the negative electrode plate, for example, the negative electrode active material, the conductive agent, the binder, and any other components, in a solvent to form a negative electrode slurry, a non-limiting example of the solvent being deionized water; and coating the negative electrode slurry on at least one side surface of the negative electrode current collector, and after processes such as drying and cold pressing, the negative electrode plate can be obtained. The surface of the negative electrode current collector on which the negative electrode slurry is coated may be a single surface of the negative electrode current collector, or may be both surfaces of the negative electrode current collector. A solid content of the negative electrode slurry may be 40 wt% to 60 wt%. A viscosity of the negative electrode slurry at room temperature may be adjusted to 2000 mPa^s to 15000 mPa^s. Electrolyte The electrolyte serves for conducting ions between the positive electrode plate and the negative electrode plate. The type of the electrolyte is not specifically limited in the present application and can be selected according to requirements. For example, the electrolyte can be liquid, gelled, or all solid. In some implementations, an electrolyte solution is used as the electrolyte. The electrolyte solution includes an electrolyte salt and a solvent. In some of the embodiments, the electrolyte salt may include one or more of lithium hexafluorophosphate (abbreviated as: LiPF6), lithium tetrafluoroborate (abbreviated as: LiBF4), lithium perchlorate (abbreviated as: LiClO4), lithium hexafluoroarsenate (abbreviated as: LiAsF6), lithium bis(fluorosulfonyl)imide (abbreviated as:       LiFSI),       lithium bis(trifluoromethanesulfonyl)imide (abbreviated as: LiTFSI), lithium trifluoromethanesulfonate (abbreviated as: LiTFS), lithium difluorophosphate (abbreviated as: LiPO2F2), lithium difluoro(oxalato)borate (abbreviated as: LiDFOB), lithium bis(oxalato)borate (abbreviated as: LiBOB), lithium difluorobis(oxalato)phosphate (abbreviated as: LiDFOP) and lithium tetrafluoro(oxalato)phosphate (abbreviated as: LiTFOP). In some of the embodiments, the solvent may include one or more of ethylene carbonate (abbreviated as: EC), the chemical formula of EC being , propylene carbonate o CrA T o (abbreviated as: PC), the chemical formula of PC being /       , ethyl methyl carbonate (abbreviated as: EMC), diethyl carbonate (abbreviated as: DEC), dimethyl carbonate (abbreviated as: DMC), dipropyl carbonate (abbreviated as: DPC), methyl propyl carbonate (abbreviated as: MPC), ethyl propyl carbonate (abbreviated as: EPC), butylene carbonate, the chemical formula of O^° r"Vo butylene carbonate being /           , fluoroethylene carbonate (abbreviated as: FEC), methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, ethyl methyl sulfone and diethyl sulfone. Optionally, when the electrolyte solution contains a cyclic carbonate, the cyclic carbonate may be one or more of EC and PC. When the electrolyte solution contains a chain carbonate, the chain carbonate may be one or more of EMC, DEC and DMC. In some of the embodiments, the electrolyte solution may optionally also include an additive. For example, the additive may include a negative electrode film-forming additive, a positive electrode film-forming additive, and may also include an additive capable of improving certain performances of the battery, for example, an additive that improves an overcharge performance of the battery, an additive that improves a high-temperature or low-temperature performance of the battery, etc. In some implementations, the additive in the electrolyte solution may also include, but is not limited to, one or more of difluoroethylene carbonate (abbreviated as: DFEC), trifluoromethyl ethylene carbonate (abbreviated as: TFPC), etc. Separator In some of the embodiments, the secondary battery further comprises a separator. The type of the separator is not particularly limited in the present application, and any well-known porous-structured separator having good chemical stability and mechanical stability may be selected. In some of the embodiments, the material of the separator may be one or more of glass fiber, non-woven cloth, polyethylene, polypropylene, and polyvinylidene fluoride. The separator may be either a single-layer thin film or a multilayer composite thin film without special limitations. When the separator is a multilayer composite thin film, the materials of the layers can be the same or different without special limitations. In some implementations, the thickness of the separator is 6 pm to 40 pm, optionally 12 pm to 20 pm. PCT / CN2025 / 083947 English translation In some of the embodiments, the positive electrode plate, the negative electrode plate, and the separator may be formed into an electrode assembly through a winding process or a lamination process. In some of the embodiments, the battery cell may include an outer package. The outer package may be used to encapsulate the aforementioned electrode assembly and electrolyte. In some of the embodiments, the outer package of the battery cell may be a hard case, for example, a hard plastic case, an aluminum case, a steel case, etc. The outer package of the battery cell may also be a soft pack, for example, a bag-type soft pack. The material of the soft pack may be plastic, and further, non-limiting examples of the plastic may include one or more of polypropylene, polybutylene terephthalate, polybutylene succinate, etc. The secondary battery includes at least one battery cell. The secondary battery may include one or more battery cells. In the present application, unless otherwise stated, the “battery cell” refers to a basic unit that can achieve mutual conversion between chemical energy and electrical energy, and further, generally at least includes a positive electrode plate, a negative electrode plate, and an electrolyte. In a charge-discharge process of a battery, active ions reciprocally intercalate and deintercalate between a positive electrode plate and a negative electrode plate. The electrolyte plays a role in conducting active ions between the positive electrode plate and the negative electrode plate. The present application has no particular limitation on the shape of the battery cell, which may be cylindrical, prismatic, or any other arbitrary shape. For example, FIG. 3 is a battery cell 1 of a prismatic structure as an example. In some of the embodiments, referring to FIG. 4, the outer package may include a case 11 and a cover plate 13. Here, the case 11 may include a bottom plate and a side plate connected to the bottom plate, and the bottom plate and the side plate enclose and form an accommodating cavity. The case 11 has an opening in communication with the accommodating cavity, and the cover plate 13 can cover the opening to close the accommodating cavity. The positive electrode plate, the negative electrode plate, and the separator may be made into an electrode assembly 12 by a winding process or a stacking process. The electrode assembly 12 is encapsulated in the accommodating cavity. An electrolyte solution infiltrates into the electrode assembly 12. The number of electrode assemblies 12 comprised in the battery cell 1 may be one or more, and may be selected by those skilled in the art according to actual requirements. The battery may be a battery module or a battery pack. The battery module comprises at least one battery cell. The number of battery cells contained in the battery module may be one or more, and an appropriate number may be selected by those skilled in the art according to the application and capacity of the battery module. PCT / CN2025 / 083947 English translation In the battery module, a plurality of battery cells may be sequentially arranged along a length direction of the battery module. Of course, any other arrangements are also possible. Furthermore, the plurality of battery cells may be fixed by fasteners. Optionally, the battery module may further include a shell having an accommodating space, in which the plurality of battery cells are accommodated. In some of the embodiments, the above battery modules may be further assembled into a battery pack, the number of battery modules contained in the battery pack may be one or more, and an appropriate number may be selected by those skilled in the art according to the application and capacity of the battery pack. The battery pack may include a battery box and a plurality of battery modules arranged in the battery box. The battery box includes an upper box and a lower box. The upper box can cover the lower box and forms an enclosed space for accommodating the battery module. The plurality of battery modules may be arranged in the battery box in any manner. In addition, the present application further provides an electrical apparatus. The electrical apparatus comprises the battery provided by the present application. The battery may be used as a power source of the electrical apparatus, or may be used as an energy storage unit of the electrical apparatus. The electrical apparatus may comprise, but is not limited to, a mobile device, an electric vehicle, an electric train, a ship, a satellite, an energy storage system, etc. The mobile device may be, for example, a mobile phone or a laptop; and the electric vehicle may be, for example, but is not limited to, an all-electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, an electric bicycle, an electric scooter, an electric golf cart, an electric truck, and the like. For the electrical apparatus, the secondary battery may be selected based on use requirements thereof. FIG. 5 is an electrical apparatus 2 as an example. The electrical apparatus is an all-electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, or the like. In order to satisfy the requirements of the electrical apparatus for high power and high energy density of the battery, the battery pack or battery module can be employed. The device used as another example can be, for example, a mobile phone, a tablet computer, a laptop, etc. The device is generally required to be light and thin and can use a battery as a power source. To make the technical problems to be solved by the present application, the technical solutions, and the beneficial effects clearer, the present application is further described below in detail with reference to embodiments and the accompanying drawings. It is clear that the described embodiments are only some, rather than all, of the embodiments of the present application. The following description of at least one exemplary embodiment is actually merely illustrative and by PCT / CN2025 / 083947 English translation no means constitutes any limitation on the present application and the use thereof. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without involving any creative effort shall fall within the scope of protection of the present application. In embodiments in which no specific technologies or conditions are indicated, technologies or conditions described in the literatures in the art or product specifications are followed. The reagents or instruments used without manufacturer indicated are all commercially available conventional products. Embodiment 1 (1) Preparation of silicon-carbon composite material Under an argon atmosphere, porous hard carbon is heated in a reactor to 500°C and maintained at the temperature for 2 h, so as to desorb air adsorbed in the porous carbon. A mixed gas of silane and argon introduced into the reactor at a gas flow rate of 4 L / min, where a volume ratio of silane to argon is 1:4. Then a rotary kiln is heated to a temperature of 600°C, and a mixed gas of acetylene and argon is introduced at a gas flow rate of 3 L / min, where a volume ratio of acetylene to argon is 1:4, so as to perform coating treatment on silicon-carbon particles. A specific surface area of the porous hard carbon is 1650 m2 / g, a pore volume is 0.78 cm3 / g, a volume of micropores having a pore size less than or equal to 2 nm is 0.6 cm3 / g, and an average pore size of the pores is 1.8 nm. A mass percentage of elemental silicon in the silicon-carbon composite material is 47%, a crystallite size of the elemental silicon is <5.5 nm, a specific capacity of the silicon-carbon composite material is 1800 mAh / g, and a Dv50 of the silicon-carbon composite material is 9 pm. (2) Preparation of positive electrode plate A positive electrode active material lithium iron phosphate (abbreviated as: LiFePO4), a conductive agent acetylene black, and a binder polyvinylidene fluoride are mixed according to a weight ratio of 97.9:0.5:1.6 and dissolved in a solvent N-methylpyrrolidone (abbreviated as: NMP) to prepare a positive electrode slurry. A moisture content of the positive electrode active material lithium iron phosphate is 200 ppm. Then the positive electrode slurry is coated on a current collector aluminum foil, and after drying, cold pressing, edge trimming, cutting, slitting and the like are performed, to obtain a positive electrode plate. A density of a positive electrode active layer in the positive electrode plate is 2.8 g / cm3. (3) Preparation of negative electrode plate A negative electrode active material, a conductive agent carbon black, a thickener CMC, a binder, and single-walled carbon nanotubes are mixed according to a weight ratio of 96.4:0.5:1:2:0.1 and dissolved in a solvent deionized water to prepare a negative electrode slurry, and the negative electrode slurry is obtained by means of a vacuum mixer. Then the negative electrode slurry is coated on a current collector copper foil, and after drying, cold pressing, edge trimming, cutting, slitting and the like are performed, to obtain a negative electrode plate. Here, the negative electrode active material is the silicon-carbon composite material and artificial graphite. Relevant parameters of the silicon-carbon composite material and artificial graphite are shown in Table 1. A Dv50 of the artificial graphite is 16 um. (4) Preparation of electrolyte solution In an argon atmosphere glove box with a moisture content <10 ppm, ethylene carbonate, ethyl methyl carbonate, and dimethyl carbonate are mixed according to a volume ratio of 3:3:4, then lithium hexafluorophosphate (abbreviated as: LiPF6) is uniformly dissolved in the solvent, and then FEC is added, to obtain an electrolyte solution. A molar concentration of LiPF6 in the electrolyte solution is 1 mol / L, and a mass percentage of FEC in the electrolyte solution is shown in Table 1. (5) Separator A porous polyethylene (abbreviated as: PP) film is used as a separator. (6) Preparation of battery cell The positive electrode plate, the separator, and the negative electrode plate are prepared in order, with the separator being positioned between the positive electrode plate and the negative electrode plate to function as isolation, and then winding, hot-press shaping, and welding are performed to obtain an electrode assembly. The electrode assembly is placed in a prismatic aluminum case, and after vacuum drying, an electrolyte solution is injected, and then standing, formation testing, aging, and capacity testing are performed, to finally obtain a battery cell with a volume of 0.411 L. Embodiments 2 to 14, Comparative Example 1 Compared with Embodiment 1, in Embodiments 2 to 14 and Comparative Example 1, the mass percentage of FEC in the electrolyte solution, the mass percentage of the silicon-carbon composite material in the negative electrode active material, the density of the negative electrode active layer, and the volumetric capacity of the negative electrode plate are different, and the details are shown in Tables 1 to 5. A density of the positive electrode active layer in Embodiments 1 to 13 and Comparative Example 1 is 2.8 g / cm3, and a density of the positive electrode active layer in Embodiment 14 is 2.4 g / cm3. Embodiment 15 Compared with Embodiment 1, the difference of Embodiment 15 lies in that the silicon-carbon composite material in Embodiment 1 is replaced with sand-milled silicon-carbon. The sand-milled silicon-carbon includes a silicon material and a carbon material coated on a surface of the silicon material. A Dv50 of the sand-milled silicon-carbon is 9 um. Comparative Example 2 PCT / CN2025 / 083947 English translation Compared with Embodiment 1, the difference of Comparative Example 2 lies in that the silicon-carbon composite material is replaced with an equal mass of a silicon-oxygen material. A Dv50 of the silicon-oxygen material is 9 um. Test Examples (1) The volumetric capacity of the negative electrode plate is tested, and the test method is: cleaning clean an active material layer on either one of two surfaces of a double-sided negative electrode plate, punching the remaining single-sided negative electrode plate into a small round piece with a radius of 7 millimeters (abbreviated as: mm) using a die, the area thereof being S=49n square millimeters (abbreviated as: mm2), measuring a thickness h of the active layer using a micrometer, obtaining a volume according to the formula V=Sh, drying the single-sided negative electrode plate with the volume V and transferring it into a glove box to fabricate a half-cell against lithium, then testing a delithiation capacity Q of the above round piece using a Wuhan LAND test equipment, and finally obtaining the volumetric capacity of the negative electrode plate by Q-V. (2) The initial coulombic efficiency and the volumetric energy density of the battery cell are tested, and the test method is: leaving the battery cell to stand in a negative pressure environment at 45°C for 20 minutes, then charging it at a rate of 0.05 coulomb (abbreviated as: C) to a 20% state of charge (abbreviated as: SOC), after winding, calculating a theoretical cell capacity C according to cathode dimensions to obtain a formation capacity C0, then leaving the battery cell to stand in an environment at 45°C for 48 h and then transferring it to normal temperature and normal pressure, charging it at a rate of 0.2 C to 3.65 volts (abbreviated as: V), and charging it at a constant voltage of 3.65 V to 0.05 C, to obtain a charge capacity C1; and finally, discharging it at a rate of 0.1 C to 2 V under normal temperature and normal pressure, to obtain a discharge capacity C2, and simultaneously obtaining a discharge energy E, the unit of E being watt-hour (abbreviated as: wh). Initial coulombic efficiency of the battery cell = C2 -(C0 + C1) * 100%. Volumetric energy density of the battery cell = E - 0.411. (3) The cycling retention rate of the battery cell is tested, and the test method is: placing the cell in an environment at 25°C, charging it at a rate of 1 C2 to 80% C2, charging it at a rate of 0.33 C2 to 3.65 V, charging it at constant voltage of 3.65 V to 0.05 C2, leaving to stand for 10 minutes, discharging it at a rate of 1 C to 10% C2, cycling the above steps 9 times, and at the 10th time, keeping the charging steps unchanged, discharging it to 2 V, to obtain a discharge capacity C10. Repeating the above steps until the cell is cycled 1000 times, obtaining a 2 V discharge capacity C1000, and calculating the capacity retention rate of the battery cell after 1000 cycles. Capacity retention rate = C1000 - C10 * 100%. Table 1 Mass percentage of FEC in electrolyte solution (%) Mass percentage of siliconcarbon composite material in negative electrode active material (%) Density of negative electrode active layer (g / cm3) Volumetric capacity of negative electrode plate (mAh / cm3) Volumetric energy density of battery cell (Wh / L) Cycling retention rate of battery cell Embodiment 1 0 1 1.6 550 420 93.80% Embodiment 2 1 6 1.55 600 437 92.70% Embodiment 3 3 6 1.55 600 436 93.30% Embodiment 4 3 10 1.55 670 451 92.40% Embodiment 5 5 12 1.5 680 456 91.00% Embodiment 6 8 12 1.5 680 454 91.50% Embodiment 7 10 12 1.5 680 452 91.20% Embodiment 15 0 1 1.6 550 420 91.5% Comparative Example 1 11 5 1.55 600 426 90.80% Comparative Example 2 0 1 1.6 550 420 89.5% As can be seen from Table 1, when the negative electrode active material includes the siliconcarbon composite material, and the mass percentage of FEC in the electrolyte solution is less than or equal to 10%, the battery cell has a relatively high energy density and relatively good cycling performance. Further, as can be seen from Embodiment 1 and Embodiment 15, when the silicon-5 carbon composite material includes a porous carbon material and a silicon material located in pores of the porous carbon material, the battery cell has a relatively high volumetric energy density and, at the same time, has better cycling performance. Table 2 Mass percentage of FEC in electrolyte solution (%) Mass percentage of silicon-carbon composite material in negative electrode active material (%) Density of negative electrode active layer (g / cm3) Volumetric capacity of negative electrode plate (mAh / cm3) Initial coulombic efficiency of battery cell Embodiment 1 0 1 1.6 550 92.10% Embodiment 8 0 5 1.6 600 91.80% Embodiment 9 0 6 1.55 600 91.80% Embodiment 10 1 1 1.6 550 91.50% As can be seen from Table 2, when the mass percentage of the silicon-carbon composite material in the negative electrode active material is 1% to 5%, and the mass percentage of FEC in the electrolyte solution is 0%, the battery cell has a relatively high initial coulombic efficiency. Table 3 Mass percentage of FEC in electrolyte solution (%) Mass percentage of silicon-carbon composite material in negative electrode active material (%) Density of negative electrode active layer (g / cm3) Volumetric capacity of negative electrode plate (mAh / cm3) Initial coulombic efficiency of battery cell Embodiment 2 1 6 1.55 600 91.60% Embodiment 3 3 6 1.55 600 91.50% Embodiment 4 3 10 1.55 670 91.10% Embodiment 11 5 6 1.6 600 90.80% 5 As can be seen from Table 3, when the mass percentage of the silicon-carbon composite material in the negative electrode active material is greater than 5% and less than or equal to 10%, and the mass percentage of FEC in the electrolyte solution is greater than 0% and less than or equal to 3%, the battery cell has a relatively high initial coulombic efficiency. Table 4 Mass percentage of FEC in electrolyte solution (%) Mass percentage of silicon-carbon composite material in negative electrode active material (%) Density of negative electrode active layer (g / cm3) Volumetric capacity of negative electrode plate (mAh / cm3) Initial coulombic efficiency of battery cell Embodiment 5 5 12 1.5 680 90.60% Embodiment 6 8 12 1.5 680 90.20% Embodiment 7 10 12 1.5 680 89.80% Embodiment 12 8 15 1.45 700 89.80% Embodiment 13 8 20 1.4 750 89.30% 10 As can be seen from Table 4, when the mass percentage of the silicon-carbon composite material in the negative electrode active material is greater than 10% and less than or equal to 25%, and the mass percentage of FEC in the electrolyte solution is greater than 3% and less than or equal to 10%, the battery cell has a relatively high initial coulombic efficiency. Table 5 Mass percentage Mass percentage Density of Volumetric capacity of Density of Initial coulombic of FEC in electrolyte solution (%) of siliconcarbon composite material in negative electrode active material (%) negative electrode active layer (g / cm3) negative electrode plate (mAh / cm3) positive electrode active layer (g / cm3) efficiency of battery cell Embodiment 3 3 6 1.55 600 2.8 91.50% Embodiment 14 3 6 1.55 600 2.4 91.60% As can be seen from Table 5, when the density of the positive electrode active layer is within a suitable range, the battery cell has a relatively high initial coulombic efficiency. The technical features of the above-described embodiments can be arbitrarily combined, and for the sake of concise description, not all possible combinations of the respective technical 5 features in the above embodiments are described; however, as long as there is no contradiction in the combination of these technical features, all such combinations should be considered as the scope disclosed in this specification. The above embodiments only describe several embodiments of the present application, which are described relatively specifically and in detail, but cannot be construed as a limitation to the 10 scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, a plurality of transformations and improvements can also be made without departing from the idea of the present application. These transformations and improvements all fall within the scope of protection of the present application. Therefore, the scope of protection of the patent of the present application shall be subject to the appended claims.

Claims

1. A lithium-ion battery cell, comprising a positive electrode plate, a negative electrode plate, and an electrolyte solution, wherein the positive electrode plate comprises a positive electrode current collector and a positive electrode active layer located on at least one surface of the positive electrode current collector, a positive electrode active material of the positive electrode active layer comprising a lithium-containing phosphate; the negative electrode plate comprises a negative electrode current collector and a negative electrode active layer located on at least one surface of the negative electrode current collector, a negative electrode active material of the negative electrode active layer comprising a silicon-carbon composite material, wherein the silicon-carbon composite material comprises a silicon material and a carbon material, the silicon material being distributed inside the carbon material or the carbon material being distributed inside the silicon material; andin the electrolyte solution, a mass percentage of fluoroethylene carbonate in the electrolyte solution is less than or equal to 10%.

2. The lithium-ion battery cell according to claim 1, wherein the carbon material comprises a carbon substrate, the carbon substrate comprising a porous carbon material and / or a fibrous carbon material.

3. The lithium-ion battery cell according to claim 2, wherein the silicon-carbon composite material comprises a porous carbon material and a silicon material located in pores of the porous carbon material.

4. The lithium-ion battery cell according to claim 3, wherein the porous carbon material comprises porous hard carbon.

5. The lithium-ion battery cell according to claim 3 or 4, wherein the porous carbon material satisfies at least one of the following characteristics:(1) a specific surface area of the porous carbon material is 1350 m2 / g to 2200 m2 / g;(2) a pore volume of the porous carbon material is 0.55 cm3 / g to 1 cm3 / g; and(3) an average pore size of the pores of the porous carbon material is 1.5 nm to 5 nm.

6. The lithium-ion battery cell according to any one of claims 3 to 5, wherein a pore volume of micropores having a pore size less than or equal to 2 nm in the porous carbon material is 0.4 cm3 / g to 0.8 cm3 / g.

7. The lithium-ion battery cell according to any one of claims 3 to 6, wherein in the siliconcarbon composite material, a mass percentage of the silicon material in the silicon-carbon composite material is 32% to 55%.

8. The lithium-ion battery cell according to any one of claims 3 to 7, wherein the silicon material comprises elemental silicon.PCT / CN2025 / 083947 English translation9. The lithium-ion battery cell according to claim 8, wherein a crystallite size of the elemental silicon is less than or equal to 5.5 nm.

10. The lithium-ion battery cell according to any one of claims 2 to 9, wherein the siliconcarbon composite material further comprises a carbon coating layer, the carbon coating layer coating at least a surface of the silicon material or the carbon substrate.

11. The lithium-ion battery cell according to claim 10, wherein the silicon material is located between the carbon substrate and the carbon coating layer.

12. The lithium-ion battery cell according to claim 1 or 2, wherein the silicon-carbon composite material comprises a fibrous carbon material and nano-silicon particles and / or a nano-silicon layer distributed on the fibrous carbon material.

13. The lithium-ion battery cell according to any one of claims 1 to 12, wherein the mass percentage of the fluoroethylene carbonate in the electrolyte solution is 1% to 10%.

14. The lithium-ion battery cell according to claim 13, wherein the mass percentage of the fluoroethylene carbonate in the electrolyte solution is 3% to 8%.

15. The lithium-ion battery cell according to any one of claims 1 to 12, wherein the electrolyte solution comprises a cyclic carbonate, and the mass percentage of the fluoroethylene carbonate in the electrolyte solution is 0.

16. The lithium-ion battery cell according to any one of claims 1 to 12, wherein a volumetric capacity of the negative electrode plate is 500 mAh / cm3 to 880 mAh / cm3, the volumetric capacity of the negative electrode plate being a product of a density of the negative electrode active layer and a specific capacity of the negative electrode active material.

17. The lithium-ion battery cell according to claim 16, wherein the density of the negative electrode active layer is 1.5 g / cm3 to 1.75 g / cm3.

18. The lithium-ion battery cell according to claim 17, wherein the density of the negative electrode active layer is 1.55 g / cm3 to 1.6 g / cm3.

19. The lithium-ion battery cell according to claim 17 or 18, wherein a mass percentage of the silicon-carbon composite material in the negative electrode active material is 1% to 5%.

20. The lithium-ion battery cell according to claim 19, wherein the negative electrode active material further comprises graphite, a mass ratio of the graphite to the silicon-carbon composite material being 99:1 to 95:5.

21. The lithium-ion battery cell according to any one of claims 17 to 20, wherein the volumetric capacity of the negative electrode plate is 500 mAh / cm3 to 600 mAh / cm3, the electrolyte solution comprises a cyclic carbonate, and the mass percentage of the fluoroethylene carbonate in the electrolyte solution is 0.PCT / CN2025 / 083947 English translation22. The lithium-ion battery cell according to claim 16, wherein the density of the negative electrode active layer is 1.35 g / cm3 to 1.6 g / cm3.

23. The lithium-ion battery cell according to claim 22, wherein the density of the negative electrode active layer is 1.45 g / cm3 to 1.55 g / cm3.

24. The lithium-ion battery cell according to claim 22 or 23, wherein the mass percentage of the silicon-carbon composite material in the negative electrode active material is greater than 5% and less than or equal to 10%.

25. The lithium-ion battery cell according to claim 24, wherein the negative electrode active material further comprises graphite, a mass ratio of the graphite to the silicon-carbon composite material being greater than or equal to 90:10 and less than 95:5.

26. The lithium-ion battery cell according to any one of claims 22 to 25, wherein the volumetric capacity of the negative electrode plate is greater than 600 mAh / cm3 and less than or equal to 670 mAh / cm3, and the mass percentage of the fluoroethylene carbonate in the electrolyte solution is greater than 0 and less than or equal to 3%.

27. The lithium-ion battery cell according to claim 16, wherein the density of the negative electrode active layer is 1.3 g / cm3 to 1.6 g / cm3.

28. The lithium-ion battery cell according to claim 27, wherein the density of the negative electrode active layer is 1.4 g / cm3 to 1.55 g / cm3.

29. The lithium-ion battery cell according to claim 27 or 28, wherein a mass percentage of the silicon-carbon composite material in the negative electrode active material is greater than 10% and less than or equal to 25%.

30. The lithium-ion battery cell according to claim 29, wherein the negative electrode active material further comprises graphite, a mass ratio of the graphite to the silicon-carbon composite material being greater than or equal to 75:25 and less than 90:10.

31. The lithium-ion battery cell according to any one of claims 27 to 30, wherein the volumetric capacity of the negative electrode plate is greater than 670 mAh / cm3 and less than or equal to 880 mAh / cm3, and the mass percentage of the fluoroethylene carbonate in the electrolyte solution is greater than 3% and less than or equal to 10%.

32. The lithium-ion battery cell according to claim 31, wherein the mass percentage of the fluoroethylene carbonate in the electrolyte solution is 5% to 8%.

33. The lithium-ion battery cell according to any one of claims 1 to 32, wherein a specific capacity of the silicon-carbon composite material is 1400 mAh / g to 2300 mAh / g.

34. The lithium-ion battery cell according to claim 33, wherein the specific capacity of the silicon-carbon composite material is 1600 mAh / g to 2000 mAh / g.PCT / CN2025 / 083947 English translation35. The lithium-ion battery cell according to any one of claims 1 to 34, wherein a Dv50 of the silicon-carbon composite material is 3 pm to 15 pm.

36. The lithium-ion battery cell according to claim 35, wherein the Dv50 of the silicon-carbon composite material is 6 pm to 10 pm.

37. The lithium-ion battery cell according to any one of claims 1 to 19 and 21 to 36, wherein the negative electrode active material further comprises graphite.

38. The lithium-ion battery cell according to claim 37, wherein a mass percentage of the graphite in the negative electrode active material is 75% to 99%.

39. The lithium-ion battery cell according to claim 37 or 38, wherein a Dv50 of the graphite is 5 pm to 20 pm.

40. The lithium-ion battery cell according to claim 39, wherein the Dv50 of the graphite is 10 pm to 18 pm.

41. The lithium-ion battery cell according to any one of claims 1 to 40, wherein the lithium-containing phosphate comprises at least one of lithium iron phosphate, a composite material of lithium iron phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon.

42. The lithium-ion battery cell according to any one of claims 1 to 41, wherein a density of the positive electrode active layer is 2.3 g / cm3 to 2.9 g / cm3.

43. The lithium-ion battery cell according to claim 42, wherein the density of the positive electrode active layer is 2.6 g / cm3 to 2.8 g / cm3.

44. The lithium-ion battery cell according to any one of claims 1 to 43, wherein a moisture content of the lithium-containing phosphate is 200 ppm to 300 ppm.

45. The lithium-ion battery cell according to any one of claims 1 to 44, wherein a lithium salt in the electrolyte solution comprises at least one of a fluorine-containing lithium phosphate salt and a fluorine-containing lithium sulfonylimide salt.

46. The lithium-ion battery cell according to claim 45, wherein the fluorine-containing lithium phosphate salt comprises lithium hexafluorophosphate.

47. The lithium-ion battery cell according to claim 45 or 46, wherein the fluorine-containing lithium sulfonylimide salt comprises at least one of lithium bis(fluorosulfonyl)imide and lithium bis(trifluoromethanesulfonyl)imide.

48. A lithium-ion battery, comprising the lithium-ion battery cell according to any one of claims 1 to 47.

49. An electrical apparatus, comprising the lithium-ion battery according to claim 48.

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