Battery monomer, battery and electric device

Abstract

The invention provides a battery monomer, a battery and a power utilization device. Development resources of the battery monomer can be reduced. The battery monomer comprises at least one first type of electrode assembly and at least one second type of electrode assembly, the capacity of the first type of electrode assembly is a first capacity, the capacity of the second type of electrode assembly is a second capacity, and the first capacity is greater than the second capacity. Therefore, by setting the number of the electrode assemblies with different capacities, the battery monomers with different capacities can be obtained, so that the battery monomers can adapt to batteries with various requirements, and the development resources of the battery monomers are saved.

Description

Technical Field

[0001] The present application relates to the field of batteries, and in particular to a battery cell, a battery and an electrical device. Background Art

[0002] Energy conservation and emission reduction are the key to the sustainable development of the automobile industry. Electric vehicles have become an important part of the sustainable development of the automobile industry due to their advantages of energy conservation and environmental protection. For electric vehicles, battery technology is an important factor related to their development. Usually, batteries are composed of multiple battery cells. In the face of the diverse needs of batteries, how to reduce the development resources of battery cells so that battery cells can adapt to various needs has become a problem that needs to be solved. Summary of the invention

[0003] The embodiments of the present application provide a battery cell, a battery, and an electrical device, which can reduce the development resources of the battery cell.

[0004] In a first aspect, a battery cell is provided, comprising at least one first type electrode assembly and at least one second type electrode assembly, wherein the capacity of the first type electrode assembly is a first capacity, and the capacity of the second type electrode assembly is a second capacity, wherein the first capacity is greater than the second capacity.

[0005] In the embodiment of the present application, the battery cell may include at least two types of electrode assemblies, for example, a first type of electrode assembly and a second type of electrode assembly, wherein the capacity of the first type of electrode assembly is a first capacity, the capacity of the second type of electrode assembly is a second capacity, and the first capacity is greater than the second capacity. In this way, by setting the number of electrode assemblies with different capacities, battery cells with different capacities can be obtained to adapt to batteries of various requirements, saving the development resources of battery cells.

[0006] In a possible implementation, at least two types of electrode assemblies in the battery cell are connected in parallel. Since the voltages of the parallel electrode assemblies are equal, this can reduce the voltage requirements for other components in the battery cell and reduce circuit complexity.

[0007] In a possible implementation, the capacities of at least two types of electrode assemblies in the battery cells are configured such that a plurality of battery cells with different capacities can be obtained by configuring the quantities of the at least two types of electrode assemblies.

[0008] In this implementation, by reasonably configuring the capacities of at least two types of electrode assemblies in a battery cell, it is possible to form a variety of battery cells with different capacity requirements by adjusting the quantities of at least two types of electrode assemblies. This reduces the development resources of the battery cells and expands the application scenarios of the battery cells, compared to designing special battery cells for each battery with different power requirements.

[0009] In a possible implementation, for the at least two types of electrode assemblies whose capacities are determined, the quantities of the at least two types of electrode assemblies in the battery cell are determined based on the capacity requirements of the battery cell.

[0010] In this implementation, the quantity of the at least two types of electrode assemblies with determined capacity can be determined based on the current capacity requirement of the battery cell. For example, for a battery with a certain power requirement, the required capacity of the battery cell in the battery can be determined, and then the quantity of each of the at least two types of electrode assemblies can be configured according to the capacity requirement of the battery cell in the battery with different power requirements.

[0011] Among them, optionally, the capacity requirement of the battery cell is determined based on the parameters of the battery, for example, the parameters of the battery include at least one of the following parameters: the size of the battery, the power of the battery, the voltage platform corresponding to the battery, and the number of battery cell strings in the battery.

[0012] In this implementation, for a battery with a certain power demand, the required capacity of the battery cells in the battery can be determined based on the parameters of the battery, such as size, power, the voltage platform corresponding to the battery, and the number of battery cells in the battery. Then, according to the capacity requirements of the battery cells in batteries with different power demands, the respective quantities of at least two types of electrode assemblies with different capacities can be configured.

[0013] In a possible implementation, the battery cell further includes a box having a containing space, the containing space being used to contain the at least two types of electrode assemblies, and the center of gravity of the at least two types of electrode assemblies is located at the center of the containing space.

[0014] Generally, electrode assemblies with different capacities have different weights. Symmetrical distribution of electrode assemblies with different weights in a battery cell box can make the weight of the battery cell more uniform and improve the structural stability of the battery cell.

[0015] In a possible implementation, the first capacity accounts for 50% to 60% of the total capacity of the first capacity and the second capacity, and the second capacity accounts for 40% to 50% of the total capacity of the first capacity and the second capacity.

[0016] The first capacity and the second capacity are set within the above range, so that the capacity difference between the first type of electrode assembly and the second type of electrode assembly is small, and a battery cell with a larger capacity can be formed by a smaller number of electrode assemblies to expand the applicable product line or business scope.

[0017] For example, the number of the first type of electrode assembly is 1, and the number of the second type of electrode assembly is 1. In this way, a battery cell with a larger capacity can be formed by using a smaller number of electrode assemblies.

[0018] In a possible implementation, the battery cell further includes a third type of electrode assembly, the capacity of the third type of electrode assembly is a third capacity, and the third capacity is smaller than the second capacity. By providing an additional third type of electrode assembly, the flexibility of combining electrode assemblies of different capacities can be improved.

[0019] In a possible implementation, the first capacity accounts for 60% to 100% of the total capacity of the first capacity and the second capacity, and the second capacity accounts for 0% to 40% of the total capacity of the first capacity and the second capacity.

[0020] Setting the first capacity and the second capacity within the above range allows a larger capacity difference between the first type of electrode assembly and the second type of electrode assembly, and enables battery cells with more capacities to be formed by a smaller number of electrode assemblies, making the capacity range of the adjustable battery cells more precise.

[0021] For example, the number of the first type of electrode assembly is one, and the number of the second type of electrode assembly is a plurality. In this way, battery cells with more capacities can be formed by flexibly setting the number of the second type of electrode assembly.

[0022] In a possible implementation, the battery cell further includes a fourth type of electrode assembly, the capacity of the fourth type of electrode assembly is a fourth capacity, and the fourth capacity is smaller than the second capacity. By providing an additional fourth type of electrode assembly, the flexibility of combining electrode assemblies of different capacities can be improved.

[0023] In a possible implementation, both the first type of electrode assembly and the second type of electrode assembly are wound electrode assemblies, or both the first type of electrode assembly and the second type of electrode assembly are laminated electrode assemblies. Using electrode assemblies of the same structure can simplify the production process.

[0024] In a possible implementation, the first type of electrode assembly is a wound electrode assembly, and the second type of electrode assembly is a laminated electrode assembly; or, the first type of electrode assembly is a laminated electrode assembly, and the second type of electrode assembly is a wound electrode assembly. The combination of a wound electrode assembly and a laminated electrode assembly can combine the advantages of both, which not only alleviates the problem of easy breakage of the corners of the wound electrode assembly, but also improves the energy density of the battery cell.

[0025] In a possible implementation, the positive electrode material of the first type of electrode assembly is a ternary material, and the positive electrode material of the second type of electrode assembly is lithium iron phosphate.

[0026] In a second aspect, a battery is provided, comprising the battery cell described in the first aspect or any possible implementation manner of the first aspect.

[0027] In a third aspect, an electrical device is provided, comprising the battery described in the second aspect or any possible implementation of the second aspect, wherein the battery is used to provide electrical energy to the electrical device. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the drawings without paying creative work.

[0029] Figure 1 It is a schematic diagram of the structure of a vehicle according to an embodiment of the present application.

[0030] Figure 2 It is a schematic diagram of the structure of a battery according to an embodiment of the present application.

[0031] Figure 3 It is a schematic block diagram of a battery cell according to an embodiment of the present application.

[0032] Figures 4 to 10 They are Figure 3 Schematic block diagram of several possible capacity configurations of battery cells shown.

[0033] Fig.11 and Fig.12 It is a schematic block diagram of the positional relationship of several possible electrode assemblies in the embodiments of the present application.

[0034] In the drawings, the drawings are not drawn to scale. DETAILED DESCRIPTION

[0035] The following detailed description and drawings of the embodiments of the present application are used to illustrate the principles of the present application, but cannot be used to limit the scope of the present application, that is, the present application is not limited to the described embodiments.

[0036] It should be noted that, unless otherwise specified, "multiple" means more than two; the terms "upper", "lower", "left", "right", "inside", "outside", etc., indicating directions or positional relationships, are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. "Vertical" is not strictly vertical, but is within the allowable error range. "Parallel" is not strictly parallel, but is within the allowable error range.

[0037] The directional words appearing in the following description are all directions shown in the figures, and do not limit the specific structure of this application. In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0038] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent 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 in this application may be combined with other embodiments.

[0039] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0040] The term "multiple" as used in the present application refers to two or more than two. Similarly, the term "multiple groups" refers to two or more than two groups, and the term "multiple sheets" refers to two or more than two sheets.

[0041] In the embodiments of the present application, the battery cell may be a secondary battery, which refers to a battery cell that can be continuously used by activating the active material by charging after the battery cell is discharged. The battery cell may be, for example, a lithium-ion battery, a sodium-ion battery, a sodium-lithium-ion battery, a lithium metal battery, a sodium metal battery, a lithium-sulfur battery, a magnesium-ion battery, a nickel-hydrogen battery, a nickel-cadmium battery, a lead-acid battery, etc., and the embodiments of the present application are not limited thereto.

[0042] A battery cell usually includes an electrode assembly. The electrode assembly includes a positive electrode sheet, a negative electrode sheet and a separator. During the charge and discharge process of the battery cell, active ions such as lithium ions are embedded and released back and forth between the positive electrode sheet and the negative electrode sheet. The separator is arranged between the positive electrode sheet and the negative electrode sheet, which can prevent a short circuit between the positive electrode sheet and the negative electrode sheet, and allow active ions to pass through. Among them, the separator can be set to multiple, respectively arranged between any adjacent positive electrode sheets and negative electrode sheets.

[0043] The battery cell also includes an electrolyte, which plays a role in conducting ions between the positive electrode and the negative electrode. The present application does not limit the type of electrolyte, which can be selected according to needs. The electrolyte can be liquid, gel or solid.

[0044] In the embodiment of the present application, the electrode assembly may be a winding structure, wherein the positive electrode sheet and the negative electrode sheet are wound to form a winding structure. The electrode assembly may also be a laminated structure, for example, the positive electrode sheet and the negative electrode sheet may be provided in a plurality, and the plurality of positive electrode sheets and the plurality of negative electrode sheets are alternately stacked. Alternatively, the positive electrode sheet may be provided in a plurality, and the negative electrode sheet may be folded to form a plurality of stacked folded sections, with a positive electrode sheet sandwiched between adjacent folded sections; or, both the positive electrode sheet and the negative electrode sheet may be folded to form a plurality of stacked folded sections.

[0045] In some embodiments, the battery cell includes a housing. The housing is used to encapsulate components such as electrode assemblies and electrolytes. The housing can be a steel housing, an aluminum housing, a plastic housing such as polypropylene, a composite metal housing such as a copper-aluminum composite housing, or an aluminum-plastic film.

[0046] The battery cells may be, for example, cylindrical battery cells, prismatic battery cells, soft-pack battery cells or battery cells of other shapes. Prismatic battery cells include square-shell battery cells, blade-shaped battery cells or polygonal prismatic batteries, among which the polygonal prismatic batteries may be hexagonal prismatic batteries, etc. This application does not impose any restrictions on this.

[0047] The battery described in the embodiments of the present application may be a single physical module including one or more battery cells to provide higher voltage and capacity. In the case of multiple battery cells, the multiple battery cells are connected in series, in parallel or in hybrid connection through a busbar, wherein hybrid connection is a mixture of series connection and parallel connection.

[0048] In order to meet the power requirements of different batteries, the specifications of battery cells are increasing. However, the development of a battery cell product is time-consuming and resource-intensive, which is not conducive to the sustainable development of the battery market.

[0049] To this end, the present application provides a battery cell, which can flexibly configure electrode assemblies of different capacities to obtain battery cells of various specifications with different capacities, thereby reducing the research and development cost of the battery cell and shortening the development cycle.

[0050] The technical solutions described in the embodiments of the present application are applicable to various devices that use batteries, such as mobile phones, portable devices, laptop computers, electric vehicles, electric toys, electric tools, electric vehicles, ships and spacecraft, for example, spacecraft include airplanes, rockets, space shuttles and spacecraft, etc.

[0051] It should be understood that the technical solutions described in the embodiments of the present application are not limited to the devices described above, but can also be applied to all devices using batteries. However, for the sake of simplicity, the following embodiments are described using electric vehicles as examples.

[0052] For example, Figure 1 As shown, it is a structural schematic diagram of a vehicle 1 according to an embodiment of the present application. The vehicle 1 may be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A motor 30, a controller 20 and a battery 10 may be arranged inside the vehicle 1. The controller 20 is used to control the battery 10 to supply power to the motor 30. For example, a battery 10 may be arranged at the bottom, front or rear of the vehicle 1. The battery 10 may be used to power the vehicle 1. For example, the battery 10 may be used as an operating power source for the vehicle 1, for the circuit system of the vehicle 1, for example, for the working power requirements during the start-up, navigation and operation of the vehicle 1. In another embodiment of the present application, the battery 10 may not only be used as an operating power source for the vehicle 1, but also as a driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0053] Figure 2 A schematic structural diagram of a battery 10 according to an embodiment of the present application is shown. The battery 10 may also be referred to as a battery pack. The battery 10 may include one or more battery cells 120. The battery 10 may also include a housing (or cover) 110, the interior of the housing 110 being a hollow structure, and the battery cells 120 being accommodated in the housing 110. The housing 110 may include two parts, referred to herein as a first housing portion 111 and a second housing portion 112, the first housing portion 111 and the second housing portion 112 being buckled together. The shapes of the first housing portion 111 and the second housing portion 112 may be determined according to the shapes of a plurality of battery cells combined, and at least one of the first housing portion 111 and the second housing portion 112 has an opening.

[0054] For example, Figure 2As shown, the first box body 111 and the second box body 112 can both be hollow structures and each have only one open surface, the openings of the first box body 111 and the second box body 112 are arranged opposite to each other, and the first box body 111 and the second box body 112 are buckled together to form a box body 110 with a closed chamber. After multiple battery cells are connected in parallel, in series or in mixed series, they are placed in the box body 110 formed by the buckling of the first box body 111 and the second box body 112.

[0055] For example, different from Figure 2 As shown, only one of the first box body 111 and the second box body 112 is a hollow cuboid with an opening, and the other is in a plate shape to cover the opening. Taking the second box body 112 as a hollow structure with only one face as an opening face and the first box body 111 as a plate-shaped example, the first box body 111 covers the opening of the second box body 112 to form a box body 110 with a closed chamber, which can be used to accommodate multiple battery cells. After multiple battery cells are connected in parallel, in series or in a mixed combination, they are placed in the box body 110 formed by buckling the first box body 111 and the second box body 112.

[0056] In addition, the battery 10 may also include other structures, such as a busbar, which is used to achieve electrical connection between multiple battery cells, such as parallel connection, series connection or mixed connection. Specifically, the busbar can achieve electrical connection between battery cells by connecting electrode terminals of the battery cells.

[0057] In order to meet different power requirements, the number of battery cells 120 can be multiple. Among them, multiple battery cells can be connected in series, in parallel or in a mixed connection; or, multiple battery cells can be connected in series, in parallel or in a mixed connection to form a battery module, and multiple battery modules can be connected in series, in parallel or in a mixed connection to form a battery 10. In other words, multiple battery cells can directly form a battery 10, or they can first form a battery module, and then the battery module can form a battery 10.

[0058] As an example, Figure 3 1 shows a schematic block diagram of a battery cell 120 according to an embodiment of the present application. The battery cell 120 includes at least two types of electrode assemblies, or multiple types of electrode assemblies, wherein at least two types of electrode assemblies have different capacities. Figure 3 As shown, the battery cell 120 includes at least two types of electrode assemblies among a first type electrode assembly 121, a second type electrode assembly 122, a third type electrode assembly 123, a fourth type electrode assembly 124, ..., and a Zth type electrode assembly.

[0059] In the embodiment of the present application, by setting the respective quantities of at least two types of electrode assemblies, battery cells 120 with different capacities can be obtained, thereby saving development resources for the battery cells 120 .

[0060] Optionally, at least two types of electrode assemblies in the battery cell 120 are connected in parallel. Since the voltages of the parallel electrode assemblies are equal, this can reduce the voltage requirements for other components in the battery cell 120 and reduce circuit complexity.

[0061] In the following, a battery cell 120 including a first type electrode assembly 121 and a second type electrode assembly 122 is taken as an example for explanation. Assume that the number of first type electrode assemblies 121 is M, the number of second type electrode assemblies 122 is N, M and N are positive integers, and M and N may be equal or unequal. M first type electrode assemblies 121 and N second type electrode assemblies 122 are connected in parallel, the capacity of each first type electrode assembly 121 is a first capacity, and the capacity of each second type electrode assembly 122 is a second capacity, wherein the first capacity is different from the second capacity, for example, the first capacity is greater than the second capacity. By configuring the values ​​of M and N, battery cells 120 of different capacities can be obtained to be suitable for batteries 10 with different voltage requirements and / or power requirements, saving development resources for battery cells 120.

[0062] It can be understood that although at least two types of electrode assemblies with different capacities are designed, in some scenarios, only one type of electrode assembly can be selected in the process of forming the battery cell 120. For example, one of the above-mentioned M and N can be 0. Wherein, in the case of M=0, N≥1, the battery cell 120 does not include the first type of electrode assembly 121, but only includes N second type of electrode assemblies 122. For battery cells 120 with different capacity requirements, the number N of the second type of electrode assemblies 122 in the battery cell 120 is different; in the case of M≥1, N=0, the battery cell 120 does not include the second type of electrode assembly 122, but only includes M first type of electrode assemblies 121. For battery cells 120 with different capacity requirements, the number M of the first type of electrode assemblies 121 in the battery cell 120 is different.

[0063] In some embodiments, by reasonably designing the capacity of at least two types of electrode assemblies, a variety of battery cells 120 with different capacities can be formed by configuring the quantity of at least two types of electrode assemblies. Compared with designing electrode assemblies of special capacities for battery cells of each capacity requirement, the development resources of the battery cells 120 can be reduced and their application scenarios can be expanded.

[0064] Furthermore, by reasonably designing the capacities of at least two types of electrode assemblies, a variety of battery cells 120 with different capacities can be formed by configuring the respective quantities of at least two types of electrode assemblies, and the number of electrode assemblies in the battery cells 120 can be kept as small as possible to reduce process complexity and cost.

[0065] In some embodiments, for the at least two types of electrode assemblies whose capacities are determined, the respective quantities of the at least two types of electrode assemblies in the battery cell 120 may be determined based on the capacity requirements of the battery cell 120 .

[0066] The capacity requirement of a battery cell 120 refers to the capacity value required to meet the power and / or voltage requirements of the battery 10 in which it is located. After determining the capacity requirement of a battery cell 120, the quantity of at least two types of electrode assemblies in the battery cell 120 can be configured according to the capacity requirement of the battery cell 120.

[0067] In the embodiment of the present application, satisfying the capacity requirement of the battery cell 120 means that the actual capacity of the battery cell 120 obtained after at least two types of electrode assemblies in the battery cell 120 are connected, for example, in parallel, is equal to or greater than the capacity requirement of the battery cell. In other words, "over-allocation" of capacity is allowed within a certain range, and the actual capacity obtained after at least two types of electrode assemblies in the battery cell 120 are connected is greater than or equal to the capacity requirement of the battery cell 120, which means that the capacity requirement of the battery cell 120 can be considered to be satisfied.

[0068] In the following, a battery cell 120 including two types of electrode assemblies, namely, a first type of electrode assembly 121 and a second type of electrode assembly 122 is taken as an example, wherein the number of the first type of electrode assemblies 121 is M, and the number of the second type of electrode assemblies 122 is N. When designing the capacity of the first type of electrode assembly 121 and the capacity of the second type of electrode assembly 122, the goal is to be able to meet various capacity requirements of the battery cell 120, so that after determining the capacity of the first type of electrode assembly 121 and the capacity of the second type of electrode assembly 122, it is possible to adjust the values ​​of M and N to obtain battery cells 120 of multiple specifications that respectively meet the various capacity requirements.

[0069] In some embodiments, the capacity requirement of the battery cell 120 can be determined based on the parameters of the battery 10 used by the battery cell 120, so that the battery 10 meets the corresponding power requirement and / or voltage requirement. For example, the parameters of the battery 10 include at least one of the following: the size of the battery 10, the power of the battery 10, the voltage platform corresponding to the battery 10, the number of battery cells 120 in series in the battery 10, etc. Among them, the number of battery cells 120 in series refers to the number of series units formed by battery cells 120 connected in series in the battery 10.

[0070] For example, for a battery 10 with a certain power requirement, the capacity requirement of the battery cells 120 in the battery 10 can be determined based on parameters of the battery 10, such as the power of the battery 10, the voltage platform corresponding to the battery 10, the number of battery cells 120 in series in the battery 10, and other parameters, and then the respective quantities of at least two types of electrode assemblies with different capacities can be configured based on the capacity requirement of the battery cells 120 in the battery 10.

[0071] Since the size and power of the battery 10 determine the volume energy density of the battery 10, the chemical system used by the battery 10 can be determined according to the volume energy density. For example, the chemical system can be lithium iron phosphate (LiFePO4, LFP) or ternary material (Ni-Co-Mn, NCM), wherein the battery cell 120 of the LFP chemical system has advantages such as high temperature stability, and the battery cell 120 of the NCM chemical system has advantages such as high energy density. Generally, the overall energy of the battery 10 can be improved by increasing the number of battery cells 120 or using battery cells 120 with high volume energy density, such as battery cells 120 using the NCM chemical system. However, increasing the number of battery cells 120 will lead to an increase in the volume and mass of the battery 10, and the safety of the battery cell 120 using the NCM chemical system is relatively poor. Therefore, first of all, it is necessary to determine the volume energy density of the battery 10 according to the size and power of the battery 10, and then select a suitable chemical system according to the volume energy density to take into account factors such as the size, power, and safety of the battery 10.

[0072] Since the voltages of battery cells 120 of different chemical systems are different, after determining the chemical system adopted by the battery 10, the voltage of the battery cell 120 can be determined. For example, taking the LFP chemical system as an example, the nominal voltage or rated voltage of the battery cell 120 can be 3.22V. It should be understood that since the rated voltage of the battery cell 120 is usually affected by the current and changes, 3.22V only represents the rated voltage of the battery cell 120 under a certain state, such as at a discharge rate of 1 / 3C.

[0073] The power of the battery 10 is the product of its capacity and voltage. The range of the number of battery cells 120 in the battery 10 can be determined by combining the required power of the battery 10 and the voltage of the battery cell 120, wherein the voltage of the battery 10 is the sum of the voltages of the battery cells 120 connected in series. For a battery 10 with a large power, if the number of battery cells 120 in series is limited by the voltage range of the battery 10, it is necessary to consider the solution of multiple battery cells 120 connected in parallel; for batteries 10 with the same power, if the battery 10 requires a higher voltage platform, the capacity of the battery cell 120 can be reduced accordingly. For example, for a voltage platform of 800V and a voltage platform of 400V, when the power remains unchanged, the capacity of the battery cell 120 in the battery 10 using the voltage platform of 800V is less than the capacity of the battery cell 120 in the battery 10 using the voltage platform of 400V. In this way, according to the power, voltage and number of battery cells 120 in series of the battery 10, the capacity requirement of the battery cell 120 can be determined.

[0074] By decomposing the capacity requirement of the battery cell 120 , an optimal combination of at least two types of electrode assemblies in the battery cell 120 can be obtained.

[0075] It should be understood that the voltage platform described in the embodiments of the present application may refer to a voltage range. For example, for a voltage platform of 400V, voltages in the range of 300V to 500V may all belong to the voltage platform of 400V.

[0076] In some embodiments, at least two types of electrode assemblies in the battery cell 120 may have different structures in addition to different capacities. For example, for the first type of electrode assembly 121 and the second type of electrode assembly 122, the first type of electrode assembly 121 and the second type of electrode assembly 122 may both be wound electrode assemblies, or the first type of electrode assembly 121 and the second type of electrode assembly 122 may both be laminated electrode assemblies. The use of electrode assemblies of the same structure can simplify the production process; for another example, one of the first type of electrode assembly 121 and the second type of electrode assembly 122 is a wound electrode assembly, and the other is a laminated electrode assembly. In this way, the combination of a wound electrode assembly and a laminated electrode assembly can combine the advantages of both, which not only alleviates the problem of easy breakage of the corners of the wound electrode assembly, but also improves the energy density of the battery cell.

[0077] In some embodiments, the chemical systems of at least two types of electrode assemblies in the battery cell 120 may also be different. For example, for the first type of electrode assembly 121 and the second type of electrode assembly 122, since the capacity of the first type of electrode assembly 121, i.e., the first capacity, is greater than the capacity of the second type of electrode assembly 122, i.e., the second capacity, the positive electrode material of the first type of electrode assembly 121 may be selected as a ternary material, and the positive electrode material of the second type of electrode assembly 122 may be selected as lithium iron phosphate, which can not only utilize the advantages of high temperature stability of the lithium iron phosphate electrode assembly, but also fully utilize the advantages of high energy density of the ternary lithium electrode assembly to compensate for the disadvantages of the lithium iron phosphate electrode assembly, thereby improving the energy density of the battery cell 120, thereby improving the overall energy of the battery cell 120 without increasing the volume and weight of the battery cell 120.

[0078] In some embodiments, the battery cell 120 includes a first type electrode assembly 121 and a second type electrode assembly 122, the capacity of the first type electrode assembly 121 is a first capacity, the capacity of the second type electrode assembly 122 is a second capacity, the first capacity is greater than the second capacity, and the number M of the first type electrode assembly 121 is less than or equal to the number N of the second type electrode assembly 122. That is, the number M of the first type electrode assembly 121 with a larger capacity is less than or equal to the number N of the second type electrode assembly 122 with a smaller capacity, thereby reducing the sum of the numbers of the first type electrode assembly 121 and the second type electrode assembly 122 as much as possible and reducing the process complexity.

[0079] For example, the number M of the first type electrode assemblies 121 is 1, and the number N of the second type electrode assemblies is 1.

[0080] For another example, the number M of the first type of electrode assemblies 121 is 1, and the number N of the second type of electrode assemblies is greater than or equal to 1.

[0081] That is, a first-type electrode assembly 121 with a larger capacity and at least one second-type electrode assembly 122 with a smaller capacity may be selected to minimize the total number of first-type electrode assemblies 121 and second-type electrode assemblies 122 in the battery cell 120 .

[0082] In some embodiments, the capacity of the first type of electrode assembly 121 may be the capacity of the battery cell 120 with the smallest capacity among multiple battery cells 120 with different capacity requirements, and the capacity of the second type of electrode assembly 122 may be less than or equal to the capacity difference between two battery cells 120 with the smallest capacity difference among the multiple battery cells 120 with different capacity requirements.

[0083] In the process of designing the capacities of the first type electrode assembly 121 and the second type electrode assembly 122, the minimum capacity can be selected as the capacity of the first type electrode assembly 121 according to the multiple capacity requirements of the battery cells 120 that need to be met, and the smallest capacity difference between any two capacities can be temporarily used as the capacity of the second type electrode assembly 122. If the configuration of one first type electrode assembly 121 and the number of electrode assemblies cannot simultaneously meet the multiple capacity requirements, the capacity of the second type electrode assembly 122 is gradually reduced, and the number of second type electrode assemblies 122 is increased until the multiple capacity requirements are met, and the adjusted capacity of the second type electrode assembly 122 is used as the final capacity of the second type electrode assembly 122.

[0084] For example, two types of electrode assemblies need to be designed, namely, a first type of electrode assembly 121 and a second type of electrode assembly 122. By combining the first type of electrode assembly 121 and the second type of electrode assembly 122, a battery cell 120 with capacity requirements of C1, C2, ..., Cn is obtained, that is, the set of n types of capacity requirements to be met is {C1, C2, ..., Cn}, n∈Z. The capacity of the first type of electrode assembly 121 is recorded as A, and the capacity of the second type of electrode assembly is recorded as B.

[0085] Among them, A=min{C1, C2, ..., Cn}, the capacity of the first type of electrode assembly 121 is the minimum capacity among n capacity requirements; B=min{Cx-Cy}, Cx∈{C1, C2, ..., Cn}, Cy∈{C1, C2, ..., Cn}, take the difference between any two capacity values ​​among multiple capacity requirements, and select the smallest capacity difference as the capacity of the second type of electrode assembly 122.

[0086] For example, as shown in Table 1, Nn is the number of the second type electrode assemblies 122, n is a positive integer, and different capacity requirements C1, C2, ..., Cn are met by configuring one first type electrode assembly 121 and Nn second type electrode assemblies 122. If a certain capacity requirement cannot be met by setting a suitable number of second type electrode assemblies, the capacity of the second type electrode assembly is gradually reduced, and the number of second type electrode assemblies Kn is increased until all capacity requirements C1, C2, ..., Cn are met.

[0087] Table 1

[0088] Capacity requirements Capacity of the first type of electrode assembly Capacity of the second type of electrode assembly Battery cell capacity C1 A N1×B A+N1×B C2 A N2×B A+N2×B C3 A N3×B A+N3×B C4 A N4×B A+N4×B …… …… …… …… Cn A Nn×B A+Nn×B

[0089] In some embodiments, the ratio of thickness to height of each type of electrode assembly in at least two types of electrode assemblies is between 0.01 and 5, and / or the ratio of height to width is between 0.02 and 16.7. That is, 0.015≤thickness / width≤5, and / or, 0.02≤height / width≤16.7. By reasonably setting the ratio of thickness to height and the ratio of height to width of the electrode assembly, the space utilization inside the battery cell 120 can be improved, the force between the electrode assemblies can be more uniform, and the utilization of the electrolyte can be improved. For example, in some embodiments, the width and height of at least two types of electrode assemblies in the battery cell 120 are the same, that is, the ratio of height to width is 1.

[0090] It can be understood that the directions in which any two of the height, width and thickness of the electrode assembly are located are perpendicular to each other. Optionally, the direction in which the height of the electrode assembly is located is a direction perpendicular to the end surface of the battery cell 120 where the electrode terminal is located. The dimensions of the electrode assembly in two of the directions can be fixed, and the capacity thereof can be changed by changing the dimensions of the electrode assembly in another direction. As an example, the height and width of at least two types of electrode assemblies can be made the same, and the capacity thereof can be changed by changing the thickness of the electrode assembly. In this way, the volume utilization rate inside the battery cell 120 can be increased, the force between the electrode assemblies can be made more uniform, and the utilization rate of the electrolyte can be increased. In addition, it is not easy for smaller-sized electrode assemblies to be suspended in mid-air or for the electrical connection portion to need to be lengthened.

[0091] In some embodiments, one of the first type electrode assembly 121 and the second type electrode assembly 122 is the electrode assembly with the largest capacity in the battery cell 120, and the other is the electrode assembly with the smallest capacity in the battery cell 120. Optionally, the ratio between the capacity of the first type electrode assembly 121 and the capacity of the second type electrode assembly 122 can be determined based on the difference between the size of the first type electrode assembly 121 and the size of the second type electrode assembly 122.

[0092] For example, the size of the electrode assembly in two directions may be fixed, and the capacity may be changed by changing the size of the electrode assembly in another direction. In this way, the capacity of the electrode assembly is associated with its size in another direction. For example, the range of the capacity ratio of the first type of electrode assembly 121 and the second type of electrode assembly 122 is determined by the ratio between the sizes of the two in the direction and the inverse of the ratio.

[0093] In order to improve the volume utilization rate inside the battery cell 120, make the force between the electrode assemblies more uniform, and improve the utilization rate of the electrolyte, the width and height of the electrode assemblies of different capacities can be configured to be consistent, wherein the direction of the height of the electrode assembly is perpendicular to the end surface of the electrode terminal on the battery cell 120. At this time, if the capacity of the electrode assembly increases with the increase of thickness, the capacity ratio between the electrode assemblies of different capacities is associated with the thickness of the electrode assembly. For example, the capacity ratio of the first type of electrode assembly 121 and the second type of electrode assembly 122 can be in the range of 0.01 to 100. Further, considering that the thickness of the electrode assembly is preferably greater than or equal to 2 mm and less than or equal to 150 mm, the capacity ratio between the electrode assemblies of different capacities should be in the range of 2 / 150 to 150 / 2, that is, the capacity ratio between the first type of electrode assembly 121 with the largest capacity and the second type of electrode assembly 122 with the smallest capacity is in the range of 0.013 to 75.

[0094] In some embodiments, the capacity of each of the at least two types of electrode assemblies of the battery cell 120 is within the range of 0Ah to 14000Ah, preferably within the range of 1Ah to 5000Ah. In this way, the difficulty of the manufacturing process of the electrode assembly can be reduced, the manufacturing quality of the electrode assembly can be improved, and the economy of the electrode assembly can be improved. For example, configuring the capacity of the electrode assembly to be greater than or equal to 1Ah can improve its economy; or configuring the capacity of the electrode assembly to be less than or equal to 5000Ah is conducive to reducing the difficulty of controlling the manufacturing process and manufacturing quality.

[0095] In addition, optionally, in order to alleviate the circulation problem between electrode assemblies, when configuring at least two types of electrode assemblies, factors such as the internal resistance of electrode assemblies of different capacities and the pressure difference between electrode assemblies of different capacities need to be considered.

[0096] In some embodiments, the size of each of the at least two types of electrode assemblies in the battery cell 120 may satisfy at least one of the following conditions: the height is in the range of 30 mm to 500 mm; the width is in the range of 30 mm to 1300 mm; the thickness is in the range of 2 mm to 150 m.

[0097] Specifically, the types of electrode assemblies generally include wound or laminated types, etc. For wound electrode assemblies, in order to reduce the risks of heat dissipation difficulties and lithium deposition at the edges and corners caused by the large thickness and width of the electrode assembly, as well as the risks of electrolyte not being easy to climb due to the large height of the electrode assembly, and the long winding needle used in the preparation process being easy to deform, and in order to improve the economy of the electrode assembly, the thickness, width and height of the wound electrode assembly are configured within a suitable range.

[0098] For stacked electrode assemblies, in order to reduce the process difficulties and difficulty in aligning the electrodes caused by the large thickness and width of the electrode assemblies, as well as the difficulty in electrolyte climbing due to the large height, and at the same time to improve the economy of the electrode assembly, the thickness, width and height of the stacked electrode assembly should also be within an appropriate range.

[0099] Therefore, setting the height of the electrode assembly within the range of 30 mm to 500 mm, setting the width of the electrode assembly within the range of 30 mm to 1300 mm, and setting the thickness of the electrode assembly within the range of 2 mm to 150 mm can not only improve the preparation quality of the electrode assembly, but also improve the economy of the electrode assembly.

[0100] Taking the battery cell 120 including the first type electrode assembly 121 and the second type electrode assembly 122 as an example, the capacity of the first type electrode assembly 121 is the first capacity, the capacity of the second type electrode assembly 122 is the second capacity, and the first capacity is greater than the second capacity. In some embodiments, the first capacity accounts for 50% to 60% of the total capacity of the first capacity and the second capacity, and the second capacity accounts for 40% to 50% of the total capacity of the first capacity and the second capacity, that is, the first capacity / (first capacity + second capacity) is between 50% and 60%, and the second capacity / (first capacity + second capacity) is between 40% and 50%.

[0101] The first capacity and the second capacity are set within the above range, so that the capacity difference between the first type electrode assembly 121 and the second type electrode assembly 122 is small, and a battery cell 120 with a larger capacity can be formed by a smaller number of electrode assemblies, thereby expanding the applicable product line or business scope.

[0102] At this time, since the difference between the first capacity and the second capacity is small, optionally, the number M of the first type of electrode assemblies 121 and the number of the second type of electrode assemblies 122 can be equal, for example, the number M of the first type of electrode assemblies 121 = 1, and the number N of the second type of electrode assemblies 122 = 1, that is, only two electrode assemblies are used to form the battery cell 120, and a battery cell 120 with a larger capacity can be formed by a minimum number of electrode assemblies.

[0103] For example, assuming that you need to design a battery cell 120 with a capacity of 180Ah, you can configure the capacities of the first type electrode assembly 121 and the second type electrode assembly 122 to be 100Ah and 80Ah respectively, that is, the first capacity is 100Ah and the second capacity is 80Ah. In this way, only one first type electrode assembly 121 and one second type electrode assembly 122 can be used to form a battery cell 120 with a capacity of 180Ah.

[0104] If it is necessary to design two battery cells 120 with different capacity requirements at the same time, where one battery cell 120 requires a capacity of 180Ah and the other battery cell 120 requires a capacity of 500Ah, the capacities of the first type electrode assembly 121 and the second type electrode assembly 122 can be configured to be 100Ah and 80Ah respectively, that is, the first capacity is 100Ah and the second capacity is 80Ah. In this case, one first type electrode assembly 121 and one second type electrode assembly 122 can be used to form a battery cell 120 with a capacity of 180Ah, and one first type electrode assembly 121 and five second type electrode assemblies 122 can be used to form a battery cell 120 with a capacity of 500Ah. Among them, the first capacity accounts for 56% of the total capacity of the first capacity and the second capacity, and the second capacity accounts for 44% of the total capacity of the first capacity and the second capacity.

[0105] It can be seen that when the capacity difference between the first type electrode assembly 121 and the second type electrode assembly 122 is small, battery cells 120 with different capacity ranges can be covered, such as the above-mentioned 180Ah battery cell 120 and 500Ah battery cell 120.

[0106] Generally, the capacity of the battery cells used in power batteries, such as passenger cars, is between 100Ah and 200Ah, while the capacity of the battery cells or energy storage batteries used in other types of vehicles may be higher, especially the capacity of energy storage batteries may be as high as hundreds or even thousands. In order to cover multiple battery cells 120 with a large capacity span at the same time, the capacity difference between the first type electrode assembly 121 and the second type electrode assembly 122 can be designed to be small, so that multiple battery cells 120 with different capacity spans are formed by combining a small number of first type electrode assemblies 121 and second type electrode assemblies 122, expanding the product line or business scope applicable to the two types of electrode assemblies.

[0107] In order to improve the flexibility of the combination of electrode assemblies of different capacities, the battery cell 120 may optionally further include a third type of electrode assembly 123, the capacity of the third type of electrode assembly 123 being a third capacity, wherein the third capacity is smaller than the second capacity, i.e., the first capacity>the second capacity>the third capacity.

[0108] In other embodiments, the first capacity accounts for 60% to 100% of the total capacity of the first capacity and the second capacity, and the second capacity accounts for 0% to 40% of the total capacity of the first capacity and the second capacity, that is, the first capacity / (first capacity+second capacity) is between 60% and 100%, and the second capacity / (first capacity+second capacity) is between 0% and 40%.

[0109] The first capacity and the second capacity are set within the above range, so that the capacity difference between the first type electrode assembly 121 and the second type electrode assembly 122 is larger, and battery cells 120 with more capacities can be formed by a smaller number of electrode assemblies, and the capacity range of the adjustable battery cells 120 is more precise.

[0110] At this time, since the first capacity is greater than the second capacity and the difference between the first capacity and the second capacity is large, optionally, the number M of first-type electrode assemblies 121 can be greater than the number of second-type electrode assemblies 122, for example, the number M of first-type electrode assemblies 121 is 1, and the number N of second-type electrode assemblies 122 is greater than 1.

[0111] For example, if it is necessary to design multiple battery cells 120 with capacities of 165Ah, 170Ah, 175Ah and 180Ah, the capacities of the first type electrode assembly 121 and the second type electrode assembly 122 can be configured to be 160Ah and 5Ah, respectively, that is, the first capacity is 160Ah and the second capacity is 5Ah. In this case, a battery cell 120 with a capacity of 165Ah can be formed by using one first type electrode assembly 121 and one second type electrode assembly 122, a battery cell 120 with a capacity of 170Ah can be formed by using one first type electrode assembly 121 and two second type electrode assemblies 122, a battery cell 120 with a capacity of 175Ah can be formed by using one first type electrode assembly 121 and three second type electrode assemblies 122, and a battery cell 120 with a capacity of 180Ah can be formed by using one first type electrode assembly 121 and four second type electrode assemblies 122. Among them, the first capacity accounts for 97% of the total capacity of the first capacity and the second capacity, and the second capacity accounts for 3% of the total capacity of the first capacity and the second capacity.

[0112] It can be seen that when the capacity difference between the first type electrode assembly 121 and the second type electrode assembly 122 is large, it is possible to flexibly set the number of second type electrode assemblies 122 to form a variety of battery cells 120 with different capacities, such as the multiple battery cells 120 in the range of 160Ah to 180Ah mentioned above, and the capacity range between the adjustable battery cells 120 is more precise.

[0113] Typically, the capacity of a battery cell used in a power battery, such as a battery cell used in a passenger car, is between 100Ah and 200Ah. However, for different manufacturers, the capacity of the battery cells 120 used may vary slightly within this range. In order to adapt to battery cells 120 from different manufacturers, a larger capacity difference can be designed between the first type electrode assembly 121 and the second type electrode assembly 122. By flexibly adjusting the number of the second type electrode assemblies 122 with small capacity, the first type electrode assemblies 121 and the second type electrode assemblies 122 can be combined to form a plurality of battery cells 120 with different capacities.

[0114] In addition, the capacities of the first type electrode assembly 121 and the second type electrode assembly 122 are similar. When the first type electrode assembly 121 and the second type electrode assembly 122 are connected in parallel, the problem of severe heating of the second type electrode assembly 122 caused by the large current difference caused by the large capacity difference between the two types of electrode assemblies can be alleviated to a certain extent; when the first type electrode assembly 121 and the second type electrode assembly 122 are connected in series, the problem of voltage overload of the first type electrode assembly 121 caused by the large voltage difference caused by the large capacity difference between the two types of electrode assemblies can be alleviated to a certain extent.

[0115] In order to improve the flexibility of the combination of electrode assemblies of different capacities, the battery cell 120 may optionally further include a fourth type of electrode assembly 124, the capacity of the fourth type of electrode assembly 124 being a fourth capacity, wherein the fourth capacity is smaller than the second capacity, i.e., the first capacity>the second capacity>the fourth capacity.

[0116] The embodiment of the present application does not limit the total number of electrode assemblies in the battery cell 120. Of course, a smaller number of electrode assemblies may be used to reduce assembly complexity while meeting the capacity requirements of the battery cell 120. For example, the total number of electrode assemblies in the battery cell 120 may be less than 10, or less than 5, or less than 4.

[0117] Below, in combination with Examples 1 to 7, taking the battery cell 120 including the first type electrode assembly 121 and the second type electrode assembly 122 as an example, the battery cell 120 of the embodiment of the present application is described in combination with several possible capacity configurations of the first type electrode assembly 121 and the second type electrode assembly 122.

[0118] Example 1

[0119] First, taking an electrode assembly with a capacity of 1Ah as an example, assuming that M≥1, N=0, that is, the battery cell 120 includes a plurality of first-type electrode assemblies 121, such as Figure 4 As shown, multiple first-type electrode assemblies 121 are connected in parallel, and the capacity of each first-type electrode assembly 121 is 1Ah. For example, as shown in Table 2, a suitable M value can be selected according to demand, and M 1Ah first-type electrode assemblies 121 are connected in parallel to form a battery cell 120 with a capacity of Mah.

[0120] Table 2

[0121] Battery cell capacity / Ah Number of 1Ah electrode assemblies / EA 1 1 2 2 3 3 4 4 …… …… 5 5

[0122] Example 2

[0123] like Figure 5 As shown, assuming that the capacity of the first type electrode assembly 121 is 3Ah, the capacity of the second type electrode assembly 122 is 2Ah, the battery cell 120 includes M first type electrode assemblies 121 and N second type electrode assemblies 122, and the M first type electrode assemblies 121 are connected in parallel with the N second type electrode assemblies 122. For example, as shown in Table 3, according to the requirements, a suitable M value and N value can be selected, and M 3Ah first type electrode assemblies 121 and N 2Ah second type electrode assemblies 122 are connected in parallel to form a battery cell 120 with a capacity of 2Ah to 11Ah.

[0124] Table 3

[0125]

[0126] By connecting M first-type electrode assemblies 121 and N second-type electrode assemblies 122 in parallel, any battery cell 120 with a capacity greater than or equal to 2 Ah can be obtained.

[0127] Optionally, the battery cell 120 further includes a third type of electrode assembly connected in parallel with the first type of electrode assembly 121 and the second type of electrode assembly 122. The number of the third type of electrode assembly can be one or more. Taking one electrode assembly as an example, the capacity of the third type of electrode assembly is 10K, and the capacity of the battery cell 120 is between 10K+2 and 10K+11, where K is a positive integer. In this way, through the combination of 10K+(2~11)Ah, a battery cell 120 with a capacity between (10K+2)Ah and (10K+11)Ah can be obtained.

[0128] For example, when K=1, a battery cell 120 of 12 to 21 Ah can be obtained by connecting a 10 Ah third-type electrode assembly, M 3 Ah first-type electrode assemblies 121 and N 2 Ah second-type electrode assemblies 122 in parallel in the manner of 10 Ah+(2 to 11) Ah.

[0129] For another example, when K=2, a battery cell 120 of 22-31Ah can be obtained by connecting a 20Ah third-type electrode assembly, M 3Ah first-type electrode assemblies 121 and N 2Ah second-type electrode assemblies 122 in parallel in the manner of 20Ah+(2-11)Ah.

[0130] For another example, when K=3, a battery cell 120 of 32-41Ah can be obtained by connecting a 30Ah third-type electrode assembly, M 3Ah first-type electrode assemblies 121 and N 2Ah second-type electrode assemblies 122 in parallel in the manner of 30Ah+(2-11)Ah.

[0131] From this, it can be seen that by connecting a 10K Ah third-type electrode assembly, M 3Ah first-type electrode assemblies 121, and N 2Ah second-type electrode assemblies 122 in parallel in the 10K+(2~11)Ah manner, a battery cell 120 with a capacity of (10K+2~10K+11)Ah can be obtained.

[0132] It can be understood that the above-mentioned capacity of 10K can also be achieved by the first type electrode assembly 121 and / or the second type electrode assembly 122, that is, the third type electrode assembly is not provided, but the capacity of 10K is achieved by a certain number of the first type electrode assembly 121 and / or the second type electrode assembly 122. In this way, the above-mentioned battery cell 120 with a capacity of (10K+2)Ah to (10K+11)Ah can also be achieved by a certain number of the first type electrode assembly 121 and / or the second type electrode assembly 122.

[0133] Example 3

[0134] For Class A and Class B pure electric vehicles (BEV), the mainstream power of the battery 10 is between 60 kWh and 85 kWh. Without considering the voltage platform, Figure 6 As shown, M=1, 1 first-type electrode assembly 121 and N second-type electrode assemblies 122 are connected in parallel, wherein the capacity of the first-type electrode assembly 121 is configured to be 173Ah, and the capacity of the second-type electrode assembly 122 is configured to be 4Ah. For example, as shown in Table 4, a suitable N value can be selected according to requirements to cover the mainstream power configurations of the battery 10 of Class A and Class B BEVs, such as 60kWh, 65kWh, 70kWh, 75kWh, 80kWh, and 85kWh.

[0135] Among them, the grade of the vehicle is determined according to its size, wheelbase, displacement, interior space and other parameters. Class A is usually a compact car, Class B is a mid-sized car, Class C is a medium-to-large car, and Class D is a long-body luxury car. Class A vehicles are further divided into A00, A0 and A.

[0136] In Table 4, as an example, the battery 10 adopts the LFP chemical system, and the nominal voltage of the battery cell 120 is a typical value when the current is 1 / 3C, that is, 3.22V.

[0137] Table 4

[0138]

[0139]

[0140] The charge of the battery 10 is the product of the capacity of the battery cell 120, the number of battery cells 120 in series, and the voltage of the battery cell 120. As mentioned above, the capacity requirement of the battery cell 120 can be determined based on parameters such as the charge of the battery 10, the voltage platform, and the number of battery cells 120 in series. Then, based on one first-type electrode assembly 121, the appropriate number N of second-type electrode assemblies 122 can be selected to obtain a battery cell 120 that meets the capacity requirement.

[0141] It can be seen from Table 4 that only two types of electrode assemblies need to be developed, namely, electrode assemblies with capacities of 173Ah and 4Ah, and battery cells 120 with various capacities can be obtained by configuring reasonable M values ​​and N values.

[0142] Example 4

[0143] For a voltage platform of 400V, the number of battery cells 120 in the battery 10 is usually about 114. Figure 6 As shown, in order to cover the mainstream power configuration of Class A and Class B passenger cars, Figure 7 As shown, M=1, 1 first-type electrode assembly 121 and N second-type electrode assemblies 122 are connected in parallel, wherein the capacity of the first-type electrode assembly 121 is configured to be 164Ah, and the capacity of the second-type electrode assembly 122 is configured to be 13.5Ah. For example, as shown in Table 5, a suitable N value can be selected for a 400V platform according to requirements to cover the mainstream power configuration of the battery 10 of Class A and Class B passenger cars, such as 60kWh, 65kWh, 70kWh, 75kWh, 80kWh, and 85kWh.

[0144] In Table 4, as an example, the battery 10 adopts the LFP chemical system, and the nominal voltage of the battery cell 120 is a typical value when the current is 1 / 3C, that is, 3.22V.

[0145] Table 5

[0146]

[0147] The charge of the battery 10 is the product of the capacity of the battery cell 120, the number of battery cells 120 in series, and the voltage of the battery cell 120. As mentioned above, the capacity requirement of the battery cell 120 can be determined based on parameters such as the charge of the battery 10, the voltage platform, and the number of battery cells 120 in series. Then, based on one first-type electrode assembly 121, the appropriate number N of second-type electrode assemblies 122 can be selected to obtain a battery cell 120 that meets the capacity requirement.

[0148] It can be seen from Table 5 that only two types of electrode assemblies need to be developed, namely, electrode assemblies with capacities of 164Ah and 13.5Ah, and battery cells 120 with various capacities can be obtained by configuring reasonable M values ​​and N values.

[0149] Table 5 takes a voltage platform of 400V as an example. A similar process can be used for other voltage platforms, such as a voltage platform of 800V, but the capacity of the battery cell 120 needs to be reduced accordingly.

[0150] Example 5

[0151] For a voltage platform of 400V, the number of battery cells 120 in the battery 10 is generally about 114. Based on Example 4, in order to expand the types of vehicles to which it is applied, for passenger cars of class A0, class A, class B and class C, the mainstream power of the battery 10 carried therein is, for example, 50kWh, 60kWh, 70kWh and 100kWh, respectively. Figure 8 As shown, M=1, 1 first-type electrode assembly 121 and N second-type electrode assemblies 122 are connected in parallel, wherein the capacity of the first-type electrode assembly 121 is configured to be 136Ah, and the capacity of the second-type electrode assembly 122 is configured to be 27.5Ah. For example, as shown in Table 6, a suitable N value can be selected according to requirements to cover the mainstream power configuration of A0, A, B and C class passenger cars.

[0152] In Table 6, as an example, the battery 10 adopts the LFP chemical system, and the nominal voltage of the battery cell 120 is a typical value when the current is 1 / 3C, that is, 3.22V.

[0153] Table 6

[0154]

[0155] The charge of the battery 10 is the product of the capacity of the battery cell 120, the number of battery cells 120 in series, and the voltage of the battery cell 120. As mentioned above, the capacity requirement of the battery cell 120 can be determined based on parameters such as the charge of the battery 10, the voltage platform, and the number of battery cells 120 in series. Then, based on one first-type electrode assembly 121, the appropriate number N of second-type electrode assemblies 122 can be selected to obtain a battery cell 120 that meets the capacity requirement.

[0156] It can be seen from Table 6 that only two types of electrode assemblies need to be developed, namely, 136Ah and 27.5Ah electrode assemblies, so that battery cells 120 with various capacities can be obtained by configuring reasonable M values ​​and N values.

[0157] Table 6 takes a voltage platform of 400V as an example. A similar process can be used for other voltage platforms, such as a voltage platform of 800V, but the capacity of the battery cell 120 needs to be reduced accordingly.

[0158] Example 6

[0159] On the basis of Example 5, in order to further reduce development resources, only one type of electrode assembly can be developed, that is, an electrode assembly with a capacity of 27.5Ah, which can also complete the mainstream power configuration of A0, A, B and C class passenger cars. Assume that M≥1, N=0, that is, the battery cell 120 includes multiple first type electrode assemblies 121, such as Fig. 9As shown, multiple first-type electrode assemblies 121 are connected in parallel, and the capacity of each first-type electrode assembly 121 is 27.5 Ah. For example, as shown in Table 7, a suitable M value can be selected according to the capacity requirement of the battery cell 120, and M 27.5 Ah first-type electrode assemblies 121 are connected in parallel to form a battery cell 120 with a capacity of 27.5 mAh.

[0160] Table 7

[0161]

[0162] Example 7

[0163] For a Class A car, the mainstream power of the battery 10 is between 60 kWh and 75 kWh. Fig.10 As shown, M=1, 1 first-type electrode assembly 121 and N second-type electrode assemblies 122 are connected in parallel, wherein the capacity of the first-type electrode assembly 121 is configured to be 166Ah, and the capacity of the second-type electrode assembly 122 is configured to be 2.5Ah. For example, as shown in Table 8, a suitable N value can be selected according to different capacity requirements of the battery cell 120 to cover the mainstream power configuration of the battery 10 of the A-class car.

[0164] Table 8

[0165]

[0166] In Table 8, as an example, the battery 10 adopts the LFP chemical system, and the nominal voltage of the battery cell 120 is a typical value when the current is 1 / 3C, that is, 3.22V.

[0167] As shown in Table 8, the longer the vehicle's cruising range, the higher the required power of the battery 10. The volume energy density of the battery 10 is determined based on the power and / or voltage requirements of the battery 10, as well as parameters such as the size of the battery 10, and the chemical system used is determined based on the level of volume energy density. Table 7 takes the LFP chemical system as an example. The typical value of the nominal voltage corresponding to the battery cell 120 of the LFP chemical system is 3.22V when the current is 1 / 3C.

[0168] According to the voltage platform adopted by the battery 10, combined with the nominal voltage of the battery cell 120 of 3.22V, the range of the number of battery cells 120 in the battery 10 can be determined. As can be seen from Table 8, for battery cells 120 with the same nominal voltage, the more the number of strings, the higher the nominal voltage required by the battery 10 because the voltages of the battery cells 120 connected in series are added.

[0169] According to the required power of the battery 10, the nominal voltage of the battery cell 120 and the number of strings, the capacity requirement of the battery cell 120 can be obtained. For example, as shown in the second row of Table 7, according to the required power of the battery 10 of 61kW, the nominal voltage of the battery cell 120 of 3.22V and the number of strings of 114, the required capacity of the battery cell 120 can be obtained as 61kWh / (3.22V×114)=166, so one first-type electrode assembly 121 is sufficient.

[0170] For another example, as shown in the third row of Table 8, based on the required power of the battery 10 of 66kW, the nominal voltage of the battery cell 120 of 3.22V and the number of strings of 120, it can be obtained that the required capacity of the battery cell 120 is 66kWh / (3.22V×120)=171Ah. Therefore, one first-type electrode assembly 121 and two second-type electrode assemblies 122 are used, and the actual capacity of the battery cell 120 is 166Ah+2.5Ah×2=171Ah.

[0171] For another example, as shown in the 5th row in Table 8, based on the battery's required power of 67kW, the nominal voltage of the battery cell 120 of 3.22V and the number of strings of 108, it can be obtained that the required capacity of the battery cell 120 is 67kWh / (3.22V×108)=193Ah. Therefore, using 1 first-type electrode assembly 121 and 11 second-type electrode assemblies 122, the actual capacity of the battery cell 120 is 166Ah+2.5Ah×12=194Ah.

[0172] In some embodiments, the battery cell 120 further includes a box body 110 having a receiving space for receiving at least two types of electrode assemblies, wherein the center of gravity of the at least two types of electrode assemblies is located at the center of the receiving space.

[0173] For example, Fig.11 and Fig.12 As shown, the battery cell 120 includes a box body 110 for accommodating at least two types of electrode assemblies. The box body 110 includes a symmetrical first accommodating space 1101 and a second accommodating space 1102. The weight of the electrode assembly located in the first accommodating space 1101 is equal to the weight of the electrode assembly located in the second accommodating space 1102.

[0174] Generally, electrode assemblies with different capacities have different weights. Symmetrical distribution of electrode assemblies with different weights in the box 110 of the battery cell 120 can make the weight of the battery cell 120 more uniform and improve the structural stability of the battery cell 120 .

[0175] For example, Fig.11For example, assuming that the battery cell 120 includes M first-type electrode assemblies 121 and N second-type electrode assemblies 122, the second-type electrode assemblies 122 can be respectively arranged on both sides of the first-type electrode assembly 121. In this way, the weight of the electrode assembly accommodated in the first accommodation space 1101 and the weight of the electrode assembly accommodated in the second accommodation space 1102 both include the sum of the weights of M / 2 first-type electrode assemblies 121 and N / 2 second-type electrode assemblies, so that the weights of the electrode assemblies in the first accommodation space 1101 and the second accommodation space 1102 are basically equal, thereby improving the structural stability of the battery cell 120.

[0176] For example, Fig.12 For example, assuming that the battery cell 120 includes 1 first-type electrode assembly 121 and N second-type electrode assemblies 122, the N second-type electrode assemblies 122 can be respectively arranged on both sides of the first-type electrode assembly 121. In this way, the weight of the electrode assembly accommodated in the first accommodating space 1101 and the weight of the electrode assembly accommodated in the second accommodating space 1102 both include the sum of 1 / 2 weight of the first-type electrode assembly 121 and weight of N / 2 second-type electrode assemblies, so that the weight of the electrode assemblies in the first accommodating space 1101 and the second accommodating space 1102 are basically equal, thereby improving the structural stability of the battery cell 120.

[0177] It can be seen from the foregoing that the battery cell 120 in the embodiment of the present application is formed by at least one first-type electrode assembly 121 and at least one second-type electrode assembly 122, and the first-type electrode assembly and the second-type electrode assembly are connected in parallel, wherein the capacity of the first-type electrode assembly 121 is the first capacity, the capacity of the second-type electrode assembly 122 is the second capacity, and the first capacity is greater than the second capacity. By configuring the number of the first-type electrode assemblies 121 and the number of the second-type electrode assemblies 122, battery cells 120 of different capacities can be combined to be suitable for batteries 10 of various requirements, saving development resources of the battery cells 120 and expanding application scenarios.

[0178] The present application also provides a battery 10, the battery 10 includes the battery cell 120 described in any of the above embodiments, the battery 10 includes one or more battery cells 120, wherein the multiple battery cells 120 can be connected in parallel, in series or in mixed connection. Optionally, the battery 10 can also include a box for accommodating the battery cells 120.

[0179] The present application also provides an electrical device, including the battery 10 described in any of the above embodiments, and the battery 10 is used to provide electrical energy to the electrical device. Figure 1 The vehicle 1 is shown.

[0180] It should be noted that, under the premise of no conflict, the various embodiments described in this application and / or the technical features in each embodiment can be arbitrarily combined with each other, and the technical solution obtained after the combination should also fall within the protection scope of this application.

[0181] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0182] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, and may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0183] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced with equivalents without departing from the scope of the present application. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that: It includes at least one first type electrode assembly and at least one second type electrode assembly, the capacity of the first type electrode assembly is a first capacity, the capacity of the second type electrode assembly is a second capacity, wherein the first capacity is greater than the second capacity.

2. The battery cell according to claim 1, characterized in that: The first capacity accounts for 50% to 60% of the total capacity of the first capacity and the second capacity, and the second capacity accounts for 40% to 50% of the total capacity of the first capacity and the second capacity.

3. The battery cell according to claim 2, characterized in that: The number of the first type of electrode assemblies is 1, and the number of the second type of electrode assemblies is 1.

4. The battery cell according to claim 2 or 3, characterized in that: The battery cell further includes a third type of electrode assembly, the capacity of the third type of electrode assembly is a third capacity, and the third capacity is smaller than the second capacity.

5. The battery cell according to claim 1, characterized in that: The first capacity accounts for 60% to 100% of the total capacity of the first capacity and the second capacity, and the second capacity accounts for 0% to 40% of the total capacity of the first capacity and the second capacity.

6. The battery cell according to claim 5, characterized in that: The number of the first type of electrode assemblies is 1, and the number of the second type of electrode assemblies is multiple.

7. The battery cell according to claim 5 or 6, characterized in that: The battery cell further includes a fourth type of electrode assembly, the capacity of the fourth type of electrode assembly is a fourth capacity, and the fourth capacity is smaller than the second capacity.

8. The battery cell according to any one of claims 1 to 7, characterized in that: The first type of electrode assembly and the second type of electrode assembly are both wound electrode assemblies, or the first type of electrode assembly and the second type of electrode assembly are both laminated electrode assemblies.

9. The battery cell according to any one of claims 1 to 7, characterized in that: The first type of electrode assembly is a wound electrode assembly, and the second type of electrode assembly is a laminated electrode assembly; or, the first type of electrode assembly is a laminated electrode assembly, and the second type of electrode assembly is a wound electrode assembly.

10. The battery cell according to any one of claims 1 to 9, characterized in that: The positive electrode material of the first type of electrode assembly is a ternary material, and the positive electrode material of the second type of electrode assembly is lithium iron phosphate.

11. The battery cell according to any one of claims 1 to 10, characterized in that: At least two types of electrode assemblies in the battery cell are connected in parallel.

12. A battery, characterized in that: The invention comprises the battery cell according to any one of claims 1 to 11.

13. An electrical device, characterized in that: The battery according to claim 12 is used to provide electrical energy to the electrical device.

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