A battery

Abstract

The application relates to the field of batteries, and discloses a battery. The battery comprises a pole column assembly and a battery cell assembly electrically connected with the pole column assembly. The pole column assembly comprises a conductive main body and a connecting piece; the battery cell assembly is electrically connected with the conductive main body through the connecting piece; the connecting piece comprises a first connecting section, a second connecting section and an intermediate connecting section; the first connecting section is connected with the battery cell assembly, the second connecting section is connected with the conductive main body; and the intermediate connecting section connects the first connecting section and the second connecting section. The above-mentioned battery matches the capacity with the area of the minimum overcurrent cross section of the intermediate connecting section, thereby ensuring the overcurrent capacity of the large-capacity battery cell and reducing the use amount of the connecting piece to a certain extent, and reducing the space occupation and cost.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery. Background Technology

[0002] The new energy vehicle and electrochemical energy storage industries continue to expand, and batteries, as the core energy storage carrier, have seen their charge-discharge efficiency become a key research focus. Round-Trip Efficiency (RTE) refers to the ratio of the energy output during charging to the energy input during charging, usually expressed as a percentage, and is a core indicator of battery energy utilization. Deterioration in RTE leads to energy waste, increased operating costs, accelerated cell temperature rise, and faster material aging, ultimately shortening battery life. Improving RTE is one of the core R&D goals in battery technology. Summary of the Invention

[0003] This application discloses a battery that can basically guarantee the overcurrent capacity of large-capacity cells while reducing space occupation to a certain extent.

[0004] In a first aspect, embodiments of this application provide a battery, including a terminal assembly and a cell assembly; the cell assembly is electrically connected to the terminal assembly; the terminal assembly includes a conductive body and a connector, and the cell assembly is electrically connected to the conductive body through the connector; The connector includes a first connecting segment, a second connecting segment, and an intermediate connecting segment. The first connecting segment is connected to the battery cell assembly, and the second connecting segment is connected to the conductive body. The intermediate connecting segment connects the first connecting segment and the second connecting segment. The battery satisfies: ; Wherein: the battery capacity is C Ah, and C≥314; the battery charge / discharge power is AW; the battery system coefficient is K, and K is the ratio of the plateau voltage to the terminal voltage in the battery; the minimum current-carrying cross-sectional area of ​​the intermediate connecting section of the connector is S1 mm. 2 .

[0005] In the battery provided in this application embodiment, the above ratio is the comprehensive electrical load index corresponding to the unit overcurrent cross-section of the connector. For large-capacity cells with a capacity C≥314, they inherently possess characteristics such as high internal resistance, large operating current base, and significant heat generation. Furthermore, the connector, as a conductive connection structure electrically connecting the conductive body and the cell assembly, concentrates all charging and discharging currents through the minimum overcurrent cross-section of the middle connection section of the connector. The size of this minimum overcurrent cross-section directly affects the cross-sectional size of the connector, and the cross-sectional area of ​​the connector significantly influences the battery's overcurrent capacity and internal space occupancy. The above ratio... The ratio cannot be too small or too large. If the ratio is less than the lower limit of 3, the minimum current-carrying cross-sectional area of ​​the intermediate connection section is too large. An excessively large cross-sectional area may cause design redundancy in the connector, which will encroach on the internal assembly space of the battery, affecting the layout of the internal battery structure, and thus affecting the battery's capacity and performance. If the ratio is greater than the upper limit of 30, the battery current is too large, the minimum current-carrying cross-sectional area of ​​the intermediate connection section is too small, and the cross-sectional size of the connector is also too small, resulting in a large internal resistance of the connector and affecting the battery's energy retention rate.

[0006] The above Due to the high current-carrying capacity of materials, large-capacity battery cells generate significant heat, and the current-carrying capacity of metallic materials increases with temperature. Therefore, it is crucial to rationally control the current-carrying capacity of connectors to prevent design redundancy. For large-capacity battery cells, the internal resistance is relatively high. The total internal resistance of a battery is the sum of the internal resistance of its structural components and the internal resistance of the battery cells. Given the inherently high internal resistance of the battery cell assembly, this application embodiment increases the area of ​​the minimum current-carrying cross-section of the intermediate connection section to reduce the internal resistance of the connectors, improve their current-carrying capacity, and thereby enhance the energy retention rate and energy conversion efficiency of the large-capacity battery.

[0007] The battery provided in this application embodiment will have the above ratio. Within the range of 3-30, the minimum current-carrying cross-section of the intermediate connection section of the connector is within a reasonable range, which improves the current-carrying capacity of the connector while keeping the space occupancy rate within a reasonable range. This reduces the capacity and energy density loss caused by structural redundancy, and alleviates the internal resistance and heat generation problems caused by the high current and high internal resistance characteristics of large-capacity cells, thereby improving the battery's capacity retention, energy conversion efficiency, operational reliability, and cycle life.

[0008] In some embodiments, the positive electrode active material of the battery includes lithium manganese iron phosphate, and the battery satisfies the following: .

[0009] In some embodiments, the positive electrode active material of the battery comprises lithium iron phosphate, and the battery satisfies the following: .

[0010] In some embodiments, C satisfies: 314 ≤ C ≤ 3000.

[0011] In some embodiments, the ratio of the battery capacity to the battery volume is VED kWh / L, wherein VED satisfies: 300≤VED≤800.

[0012] In some embodiments, the battery further includes a cover plate, and the terminal assembly is disposed on the cover plate; the size of the battery in a first direction is larger than the size of the battery in a second direction, and the first direction, the second direction, and a third direction are perpendicular to each other; the third direction is the arrangement direction of the cover plate and the cell assembly; A plane perpendicular to the third direction is defined as a reference plane, and the cell assembly forms a solder mark with the first connecting segment; the orthographic projection of the solder mark on the reference plane is the first projection; the projection of the area where the second connecting segment is connected to the conductive body on the reference plane is the second projection; along the second direction, the first projection and the second projection at least partially overlap. The maximum dimension of the minimum current-carrying cross section of the intermediate connecting section in the first direction is L mm, and the dimension of the battery in the first direction is L1 mm. L and L1 satisfy the following: .

[0013] In some embodiments, the dimension of the connector in the second direction is W2 mm, and the dimension of the battery in the second direction is W1 mm, wherein W2 and W1 satisfy: .

[0014] In some embodiments, the dimension of the connector in the third direction is W mm, and the dimension of the battery in the third direction is H1 mm, wherein W and H1 satisfy: .

[0015] In some embodiments, the area of ​​the smallest cross-section of the conductive body perpendicular to the third direction is S² mm. 2 S2 and S1 satisfy: .

[0016] In some embodiments, the battery further includes a cover plate, and the terminal assembly is disposed on the cover plate; the size of the battery in a first direction is larger than the size of the battery in a second direction, and the first direction, the second direction, and a third direction are perpendicular to each other; the third direction is the arrangement direction of the cover plate and the cell assembly; A plane perpendicular to the third direction is defined as a reference plane, and the cell assembly forms a solder mark with the first connecting segment; the orthographic projection of the solder mark on the reference plane is the first projection; the projection of the area where the second connecting segment is connected to the conductive body on the reference plane is the second projection; along the second direction, the first projection and the second projection do not overlap; The minimum current-carrying cross-section of the intermediate connecting section has a maximum dimension of L mm in the second direction, and the battery has a dimension of W1 mm ​​in the first direction. L and W1 satisfy the following: .

[0017] Secondly, embodiments of this application provide an electrical device, including an electrical structure and a battery as described in any one of the first aspects; the battery is electrically connected to the electrical structure and is used to supply power to the electrical structure. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of an electrical device in an embodiment of this application; Figure 2 This is a schematic diagram of a battery structure in one embodiment of this application; Figure 3 This is a schematic diagram of the internal structure of a battery in one embodiment of this application; Figure 4 for Figure 3 Enlarged view of point A in the middle; Figure 5 This is a schematic diagram of a structure for welding the cell assembly and the terminal assembly in an embodiment of this application; Figure 6 for Figure 5 Enlarged view at point B in the middle; Figure 7 This is a schematic diagram of one possible structure of a cover plate; Figure 8 A schematic diagram of a first partial structure for welding battery cell assembly and terminal assembly; Figure 9 This is a schematic diagram of a second partial structure for welding the cell assembly and the terminal assembly; Figure 10 This is a schematic diagram of a third partial structure for welding battery cell assembly and terminal assembly; Icons: 100-Battery; 200-Electrical structure; 110-Terminal assembly; 120-Cell assembly; 131-Cover plate; 132-Housing; 111-Conductive body; 112-Connector; 121-Cell body; 122-Taper; 1221-Solder mark. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application. In the description of the embodiments of this application, unless otherwise stated, " / " means "or", for example, A / B can mean A or B; "and / or" in the text is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone.

[0020] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature, and in the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more.

[0021] Figure 1 This is a schematic diagram of the structure of an electrical device in an embodiment of this application.

[0022] like Figure 1 As shown, the power-consuming device includes a battery 100 and a power-consuming structure 200; the battery 100 is electrically connected to the power-consuming structure 200 and is used to supply power to the power-consuming structure 200.

[0023] In the aforementioned electrical device, battery 100 supplies power to electrical structure 200. This electrical device can be an energy storage cabinet or energy storage box. It can also be used for vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, but are not limited to these. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc.; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc.

[0024] Figure 1 The example shown is of an energy storage cabinet, but it is not intended to limit the electrical devices used in the embodiments of this application. Figure 1As shown, the energy storage cabinet vehicle includes a cabinet, an electrical structure 200, and a battery 100 disposed inside the cabinet. The electrical structure 200 may include functional components such as a power conversion module, a power distribution control module, and an external power supply interface.

[0025] Battery 100 refers to a battery that can be recharged after discharge to activate its active materials and continue to be used. Types of batteries 100 include nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, lithium-ion batteries, and polymer lithium-ion batteries.

[0026] The round-trip efficiency of a battery reflects the degree of energy loss during storage and conversion. This energy loss is caused by factors including, but not limited to, heat generated by the total internal resistance of the battery cells. The total internal resistance of the battery cells includes the internal resistance of the cell itself and the internal resistance of internal structural components such as tabs, solder marks, and terminals. However, the internal resistance of the cell itself is primarily constrained by the material system. Currently, battery cell materials are relatively mature, making improvements to round-trip efficiency by reducing the internal resistance of the cell itself quite limited. Therefore, current approaches tend to focus on improving the round-trip efficiency of batteries by addressing the internal structural components of the cell.

[0027] In existing methods for improving round-trip efficiency, thickening the connector is a primary approach to enhance the current-carrying capacity of the connection between the cell and the terminal, which leads to increased battery space requirements and costs. Therefore, finding a balance between battery current-carrying capacity and battery space requirements is a problem that needs to be explored.

[0028] Based on this, embodiments of this application provide a battery that improves overcurrent capability to match battery capacity while reducing battery space occupation, thereby improving battery round-trip efficiency.

[0029] Figure 2 This is a schematic diagram of a battery structure in one embodiment of this application. Figure 3 This is a schematic diagram of the internal structure of a battery in one embodiment of this application. Figure 4 for Figure 3 Enlarged view at point A in the middle. Figure 5 This is a schematic diagram of a structure for welding the cell assembly and the terminal assembly in an embodiment of this application. Figure 6 for Figure 5 Enlarged view at point B in the middle; Figure 7 This is a schematic diagram of one type of cover plate.

[0030] like Figures 2 to 7As shown, the battery provided in this embodiment includes a terminal assembly 110 and a cell assembly 120, which are electrically connected. The terminal assembly 110 includes a conductive body 111 and a connector 112; the cell assembly 120 is electrically connected to the conductive body 111 via the connector 112; the connector 112 includes a first connecting segment, a second connecting segment, and an intermediate connecting segment, the first connecting segment being connected to the cell assembly 120, the second connecting segment being connected to the conductive body 111, and the intermediate connecting segment connecting the first connecting segment and the second connecting segment.

[0031] The above batteries meet the following requirements: ; Wherein: the battery capacity is C Ah, and C≥314; the battery charge / discharge power is AW; the battery system coefficient is K, and K is the ratio of the plateau voltage to the terminal voltage in the battery; the minimum current-carrying cross-sectional area of ​​the intermediate connection section of connector 112 is S1 mm. 2 The ratio mentioned above can be 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, or any value between 3 and 30. In some implementations, the ratio is 3. In other implementations, the ratio is 30.

[0032] In the battery provided in this application embodiment, the above ratio is the comprehensive electrical load index corresponding to the unit overcurrent cross-section of the connector 112. For large-capacity cells with C≥314, they inherently have characteristics such as high internal resistance, large operating current base, and prominent heat generation. Furthermore, as a conductive connection structure electrically connecting the conductive body 111 and the cell assembly 120, all charging and discharging currents are concentrated through the minimum overcurrent cross-section of the intermediate connection section of the connector 112. The size of this minimum overcurrent cross-section directly affects the cross-sectional size of the connector 112, and the cross-sectional area of ​​the connector 112 significantly affects the battery's overcurrent capacity and internal space occupancy. The above ratio... The ratio cannot be too small or too large. If the ratio is less than the lower limit of 3, the minimum current-carrying cross-sectional area of ​​the intermediate connecting section is too large. An excessively large cross-sectional area may cause design redundancy in the connector 112. This design redundancy will encroach on the internal assembly space of the battery, affecting the layout of the internal battery structure, and thus affecting the battery's capacity and performance. If the ratio is greater than the upper limit of 30, the battery current is too large, the minimum current-carrying cross-sectional area of ​​the intermediate connecting section is too small, and the cross-sectional size of the connector 112 is also too small, resulting in a large internal resistance of the connector 112, which affects the battery's energy retention rate.

[0033] The above Due to the high current-carrying capacity of materials, large-capacity battery cells generate significant heat, and the current-carrying capacity of metallic materials increases with temperature. Therefore, it is crucial to rationally control the current-carrying capacity of connectors to prevent design redundancy. For large-capacity battery cells, the internal resistance is relatively high. The total internal resistance of a battery is the sum of the internal resistance of its structural components and the internal resistance of the battery cells. Given the inherently high internal resistance of the battery cell assembly, this embodiment of the application increases the area of ​​the minimum current-carrying cross-section of the intermediate connection section to reduce the internal resistance of connector 112, improve the current-carrying capacity of connector 112, and thereby enhance the energy retention rate and energy conversion efficiency of the large-capacity battery.

[0034] The battery provided in this application embodiment limits the aforementioned ratio to the range of 3-30, and the minimum current-carrying cross-section of the intermediate connection section of the connector is within a reasonable range. This improves the current-carrying capacity of the connector 112 while keeping the space occupancy rate within a reasonable range. This reduces capacity and energy density losses caused by structural redundancy, and alleviates the internal resistance and heat generation problems caused by the high current and high internal resistance characteristics of large-capacity cells, thereby improving the battery's capacity retention rate, energy conversion efficiency, operational reliability, and cycle life.

[0035] It is understandable that A above represents the charging and discharging power. Taking A as an example of 0.5P, the system's rated power is 0.5 times its energy capacity. For example, a 20 MWh system with 10 MW power output, 10 MW / 20 MWh equals 0.5, which is a 0.5 P system. Under constant power conditions, the battery's operating current approximately satisfies: ; The aforementioned K represents the ratio of the platform voltage to the terminal voltage, which is an overcurrent design factor for a large-capacity energy storage cell. For the same system, K is a constant. For large-capacity cells, due to their large capacity, the heat generated during battery cycling is significant, requiring a larger overcurrent capability to match the battery's energy conversion efficiency. In the embodiments of this application, the overcurrent capability is increased by multiplying by a factor K.

[0036] In some embodiments, the method for determining the battery plateau voltage is as follows: Under preset temperature conditions, a constant power charge-discharge test is performed on the battery cell under test, with the constant power level set to a predetermined proportion of the cell's rated power (e.g., 0.5P). During this constant power charge-discharge process, voltage, current, capacity, and time data are continuously collected, and the energy and capacity of the charge-discharge process are statistically analyzed. The average operating voltage of the battery cell under this power condition is characterized by the energy corresponding to a unit capacity, which can also be called the plateau voltage, i.e.: The average voltage value under the corresponding operating condition is obtained by the ratio of the total energy obtained during the charging and discharging process to the total capacity; this average voltage value is used to characterize the actual operating voltage level of the battery cell at a given power rate.

[0037] To improve the representativeness of the platform voltage characterization, the above energy and capacity statistics can correspond to a preset state of charge (SOC) range or a preset voltage range to reduce the impact of polarization at the charging and discharging ends on the average value.

[0038] In some embodiments, the method for measuring the battery terminal voltage is as follows: To improve the accuracy of SOC (close to 0% or close to 100%) voltage measurement, the terminal voltage characteristics can be obtained by using a small current adjustment at the end and segmented static monitoring during the process. The terminal voltage can be obtained by testing in the charging and / or discharging directions. For example, the qualitative steps are as follows: Charging direction (from 0% to 100%): First, adjust the battery cell to a state close to the low SOC end (0% SOC-20% SOC); In the low SOC end state, a relatively small charging current (less than or equal to 0.5C) is used to initially charge the cell to reduce the impact of end polarization on voltage determination; In the intermediate SOC range (20% SOC-85% SOC), a relatively large charging current (greater than 0.5C and less than 5C) is used for charging to improve testing efficiency; When approaching the high SOC end (85% SOC-100% SOC), switch to a relatively small charging current (less than or equal to 0.5C) for the final stage of charging; During the charging process, multiple SOC nodes are set according to the preset SOC step size (2% SOC-5% SOC), and a resting period (1-5h) is set at each SOC node, and the voltage at the end of the resting period is recorded. This allows us to obtain the quasi-balanced voltage characteristics of the cell near the high SOC end, and to determine or characterize the charging end voltage accordingly.

[0039] Discharge direction (from 100% to 0%): First, adjust the battery cells to a state close to 100% SOC. Initial discharge is performed at the 100% SOC terminal using a relatively small discharge current (less than or equal to 0.5C); Discharge using a relatively large discharge current (greater than 0.5C and less than 5C) in the middle SOC range (20% SOC-85% SOC); When approaching the low SOC end (0% SOC-20% SOC), switch to a relatively small discharge current (less than or equal to 0.5C) for the final discharge stage; During the discharge process, multiple SOC nodes are set according to the preset SOC step size (2%SOC-5%SOC), and a resting stage (1-5h) is set at each SOC node, and the voltage at the end of the resting stage is recorded. This allows us to obtain the quasi-balance voltage characteristics of the cell near the low SOC end (0% SOC), and to determine or characterize the discharge end voltage accordingly.

[0040] The above-mentioned segmented current and segmented rest are designed to balance testing efficiency with the accuracy of end voltage determination; the rested end voltage can be used to characterize the end voltage characteristics under quasi-equilibrium conditions.

[0041] The connector 112 in the aforementioned pole assembly 110 can be configured in various ways. For example, the connector 112 and the conductive body 111 can be separate structures; or the connector 112 and the conductive body 111 can be integrally formed structures.

[0042] In the embodiment where the connector 112 and the conductive body 111 are separate structures, taking the connector 112 as an adapter piece as an example, the battery cell assembly 120 is welded to the adapter piece, and the adapter piece is welded to the conductive body 111 to achieve electrical connection between the battery cell assembly 120 and the conductive body 111.

[0043] In the embodiment where the connector 112 and the conductive body 111 are integrally formed, the battery cell assembly 120 is welded to the connector 112, thereby achieving an electrical connection between the battery cell assembly 120 and the conductive body 111. There is no boundary between the connector 112 and the conductive body 111, and no contact resistance between them, thus reducing the resistance between the battery cell assembly 120 and the conductive body 111, and consequently reducing the current loss conducted from the battery cell assembly 120 to the conductive body 111.

[0044] like Figures 2 to 4 As shown, the battery 100 includes a terminal assembly 110, a cell assembly 120, a cover plate 131, and a housing 132. The housing 132 has an internal accommodating space, and one end of the housing 132 has an opening, allowing the cell assembly 120 to be accommodated within the internal accommodating space of the housing 132. The cover plate 131 covers the opening of the housing 132 and is fixedly connected to the housing 132, thus creating a relatively sealed interior. The terminal assembly 110 is disposed on the cover plate 131.

[0045] like Figure 3 and Figure 4As shown, the battery 100 includes two cell assemblies 120 and a connector 112 connecting the two cell assemblies 120; each cell assembly 120 includes a cell body 121 and a tab 122; the two cell assemblies 120 are arranged side by side, and the arrangement direction of the tabs 122 in one cell assembly 120 and the tabs 122 in the other cell assembly 120 is the same as the arrangement direction of the two cell assemblies 120; the tabs 122 in any one cell assembly 120 are bent toward the other cell assembly 120; one end of the connector 112 is electrically connected to the tab 122 in one cell assembly 120, and the other end is electrically connected to the tab 122 in the other cell assembly 120.

[0046] In some embodiments, the battery cell assembly 120 is formed by winding or stacking positive electrode sheets, a separator, and negative electrode sheets. The positive and negative electrode sheets are separated by a separator to prevent the positive and negative electrode sheets from coming into contact and causing a short circuit.

[0047] In some embodiments, the positive electrode includes a positive current collector and a positive active material layer, the positive active material layer being coated on a portion of the surface of the positive current collector. The negative electrode includes a negative current collector and a negative active material layer, the negative active material layer being coated on a portion of the surface of the negative current collector.

[0048] For example, in a lithium-ion battery, the positive electrode current collector can be made of aluminum. The positive electrode active material layer can include a positive electrode active material, such as lithium iron phosphate or lithium manganese iron phosphate. The negative electrode current collector can be made of copper. The negative electrode active material layer can include a negative electrode active material, such as carbon or silicon. The separator material can be, for example, PP (polypropylene) or PE (polyethylene).

[0049] In some embodiments of this application, the battery is a lithium manganese iron phosphate battery, that is, the positive electrode active material of the battery includes lithium manganese iron phosphate; the above battery satisfies: .

[0050] Lithium manganese iron phosphate is used as the material for the positive electrode active layer of a battery. For example, lithium manganese iron phosphate refers to LiMn... x Fe 1-x PO4 cathode system. The above ratios... Specifically, the ratio can be 4, 5, 5.8, 6, 6.9, 7, 7.0, 7.2, 7.7, 8, 8.4, 9, 9.3, 10, 10.1, 10.6, 11, 12, 12.3, 13, 13.9, 14, 14.8, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, or any value between 4 and 30. In some implementations, the positive electrode active material of the battery includes lithium manganese iron phosphate, and the above ratio is 4. In other implementations, the positive electrode active material of the battery includes lithium manganese iron phosphate, and the above ratio is 30.

[0051] For high-capacity batteries using lithium manganese iron phosphate (LMFP) as the positive electrode active material, this material possesses inherent properties such as dual discharge voltage platforms (high and low) and slightly higher intrinsic internal resistance. Furthermore, the differentiation between the high and low voltage platforms intensifies under high-current conditions. The system coefficient K is the ratio of the plateau voltage to the terminal voltage. The dual-plateau characteristic causes K to fluctuate over a wider range depending on the discharge stage and current magnitude, with a significant decrease in K during the low-voltage plateau stage. Limiting this ratio to the range of 4-30 can accommodate the material characteristics of lithium manganese iron phosphate. The lower limit of 4 can limit excessive redundancy in the minimum overcurrent cross-sectional area of ​​the intermediate connection section of connector 112 while ensuring basic overcurrent capacity, preventing connector 112 from encroaching on the assembly space of the cell body 121 to ensure the capacity retention rate of the high-capacity cell. This lower limit can cover the condition where K is small under low-voltage plateau conditions, preventing a sudden drop in the ratio during the low-plateau stage from leading to insufficient utilization of the connector cross-section, thus maintaining the overcurrent load of connector 112 within a reasonable range under both high and low voltage platforms.

[0052] In other embodiments of this application, the battery is a lithium iron phosphate battery, that is, the positive electrode active material of the battery includes lithium iron phosphate; the above-mentioned battery satisfies: .

[0053] Lithium iron phosphate (LFP) is the material used in the positive electrode active layer of the battery. For example, LFP refers to the LiFePO4 positive electrode system. The aforementioned ratio can specifically be 3, 3.8, 3.9, 4, 4.5, 4.6, 5, 5.5, 6, 7, 7.1, 7.2, 8, 9, 9.2, 10, 10.7, 11, 12, 12.5, 13, 14, 14.4, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, or any value between 3 and 25. In some implementations, the positive electrode active material of the battery includes LFP, and the aforementioned ratio is 3. In other implementations, the positive electrode active material of the battery includes LFP, and the aforementioned ratio is 25.

[0054] For high-capacity batteries using lithium iron phosphate (LFP) as the positive electrode active material, LFP inherently possesses a very flat voltage plateau, and the lower the current, the stronger the voltage stability. Under low-current conditions, the discharge voltage shows almost no drop. This characteristic is related to the coefficient K of the battery's conductivity system. This coefficient K exhibits extremely high stability, almost unaffected by the depth of discharge or small current fluctuations, with a very narrow range of numerical fluctuation. The upper limit of 25 essentially ensures sufficient overcurrent area to reduce the internal resistance of connector 112, thereby reducing the ohmic voltage drop and Joule heat generation caused by connector 112 and preventing voltage drops caused by structural internal resistance from undermining the inherent material advantage of the flat voltage plateau of LFP. Under low-current and low-polarity conditions, it further reduces conductivity losses, maintains high voltage output stability, and ensures the battery's energy conversion efficiency and energy retention rate.

[0055] In some embodiments, C satisfies: 314 ≤ C ≤ 3000. For example, C can be 314, 315, 400, 500, 530, 531, 533, 534, 600, 700, 790, 791, 794, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500, 2600, 2700, 2800, 2900, 3000, or any value between 314 and 3000. In some implementations, the battery capacity is 314 Ah. In other implementations, the battery capacity is 3000 Ah.

[0056] Limiting the C in the battery to the range of 314≤C≤3000 is an optimized design that balances space utilization and energy efficiency, based on the principle that higher capacity requirements require higher current carrying capacity.

[0057] In some embodiments, the ratio of battery capacity to battery volume is VED kWh / L, where VED satisfies: 300 ≤ VED ≤ 800. For example, VED can be 300, 350, 400, 450, 500, 550, 600, or any value between 300 and 800. In some implementations, VED is 300. In other implementations, VED is 800.

[0058] The aforementioned VED (Volume Energy Density) measures the energy output capability within a limited casing space. Its value is determined by the space ratio of the cell body 121 and the space occupied by the conductive structures, and it is highly correlated with the battery's overcurrent capability and energy conversion efficiency. However, within a fixed casing space, there is a spatial inverse relationship between the cell body 121 (carrying the active material) and the conductive body 111, connectors 112, and other conductive overcurrent structures. Excessively compressing the space of the conductive overcurrent structures to increase the cell volume ratio leads to insufficient overcurrent cross-sectional area, increased internal resistance, and aggravated Joule heat loss, resulting in a decrease in the actual output energy of the battery and thus lowering the effective volume energy density. Conversely, excessively increasing the cross-sectional area of ​​the conductive structures to ensure overcurrent capability will squeeze the space of the cell body 121, reducing capacity and directly lowering the volume energy density. Limiting VED to the range of 300-600 effectively balances the above relationships.

[0059] The lower limit of 300 limits the minimum space ratio of the cell body 121, avoiding excessive redundancy of conductive structures such as conductive body 111 and connector 112 that occupy space, ensuring that the rated capacity can be efficiently converted into output energy, and avoiding energy density waste caused by insufficient space utilization.

[0060] The upper limit of 800 defines the reasonable boundary of VED. On the one hand, it is limited by the upper limit of the energy density of the positive electrode active material of the battery itself. On the other hand, if the volume energy density exceeds this limit, the layout space of the conductive overcurrent structure needs to be compressed to the extreme, resulting in insufficient overcurrent cross-sectional area. For large-capacity cells, the internal resistance heating and energy loss will be significantly aggravated under high current conditions, the energy retention rate and conversion efficiency will decrease, the actual effective energy density cannot be improved at the same time, and it will also bring problems such as insufficient overcurrent reliability and increased safety hazards.

[0061] Within the range of 300-800, a reasonable cell space ratio can ensure large-capacity output capability, while reserving sufficient space for the conductive structure to match the overcurrent requirements of large-capacity cells, ultimately achieving optimal synergy between capacity and energy conversion efficiency per unit volume.

[0062] Figure 8 A schematic diagram of a first partial structure for welding battery cell assembly and terminal assembly; Figure 9 This is a schematic diagram of a second partial structure for welding the cell assembly and the terminal assembly; Figure 10 This is a schematic diagram of a third partial structure for welding the cell assembly and the terminal assembly.

[0063] The battery's dimension in the first direction is larger than its dimension in the second direction. The first, second, and third directions are perpendicular to each other, with the third direction being the arrangement direction of the cover plate 131 and the cell assembly 120. The first direction is... Figure 2 The X-axis can be understood as the length direction of the battery. The second direction is... Figure 2 The Y-axis can be understood as the width direction of the battery, or it can also be called the thickness direction. The third direction is... Figure 2 The Z-direction can be understood as the height direction of the battery. The two tabs 122 connected to the two cell assemblies 120 are arranged along the second direction.

[0064] The tab 122 is welded to the connector 112 to form a solder mark 1221. The position of the conductive body 111 relative to the solder mark 1221 can be selected in various ways during specific installations. For example, as... Figure 8 and Figure 9 As shown, the conductive body 111 is located in the area directly opposite the two tabs 122 that are correspondingly connected to the two battery cell assemblies 120. Alternatively, as... Figure 10 As shown, the conductive body 111 is located outside the area directly opposite the two tabs 122 that are connected to the two battery cell assemblies 120.

[0065] In some embodiments where the aforementioned conductive body 111 is located in the area directly opposite the two tabs 122 corresponding to the two cell assemblies 120, a plane perpendicular to a third direction is defined as a reference plane, and the cell assembly 120 forms a solder mark 1221 with the first connecting segment; the orthographic projection of the solder mark 1221 on the reference plane is the first projection; the projection of the area where the second connecting segment is connected to the conductive body 111 on the reference plane is the second projection; along the second direction, the first projection and the second projection at least partially overlap; the maximum dimension of the minimum current-carrying cross section of the intermediate connecting segment in the first direction is L mm, and the dimension of the battery in the first direction is L1 mm, where L and L1 satisfy: .

[0066] It is understandable that as the position of the conductive body 111 relative to the solder mark 1221 changes, the minimum current-carrying cross section of the intermediate connection section also changes accordingly. In the embodiment where the conductive body 111 is located in the area directly opposite to the two tabs 122 of the two cell assemblies 120 connected to each other, the solder mark 1221 has two edges that are opposite to each other along a first direction; along the first direction, the orthographic projection of the conductive body 111 on the connector 112 is at least partially located between the two edges. During the process of the current flowing into the solder mark 1221 being guided from the connector 112 to the conductive body 111, the current direction is parallel to the second direction, that is, parallel to the thickness direction of the battery. At this time, the minimum current-carrying cross section of the intermediate connection section is perpendicular to the second direction. The dimension of the minimum current-carrying cross section of the intermediate connection section in the direction perpendicular to the axial direction of the conductive body 111 can be understood as the maximum dimension L of the minimum current-carrying cross section in the first direction, or it can be understood as the dimension of the connector 112 in the first direction. For example, the minimum current-carrying cross section of the intermediate connection section is rectangular or quasi-rectangular. The maximum dimension of the minimum current-carrying cross section in the first direction can be understood as the length direction of the minimum current-carrying cross section. In this type of embodiment, the length direction of the minimum current-passing cross section is consistent with the length direction of the battery.

[0067] When the length direction of the minimum flow cross section of the intermediate connecting section is consistent with the length direction of the battery, the size of the flow cross section can be expanded by utilizing the internal space in the length direction of the battery, thereby improving the current carrying capacity of the connector 112. However, key functional structural components such as explosion-proof valves and liquid injection holes need to be installed in the area in the length direction of the battery. The extension size of the connector 112 and the space for the installation of these structures are inversely related. It intuitively represents the proportion of space occupied by the minimum current-carrying cross section of the intermediate connection section in the length direction of the battery.

[0068] This application embodiment limits the ratio of the maximum dimension of the minimum current-carrying cross section of the intermediate connecting section along the first direction to the dimension of the battery in the first direction to the range of 0.05-0.25. This is a synergistic optimization of the current-carrying capacity, internal structural layout integrity, and process safety of the connector 112. For example, this ratio can be any value between 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.2, 0.21, 0.22, 0.23, 0.24, 0.25, or 0.05-0.25.

[0069] The lower limit of 0.05 defines the minimum threshold for the current-carrying length of the intermediate connection section. If the proportion is lower than this value, the connector 112 cannot fully utilize the spatial advantage along the length of the battery. Insufficient current-carrying cross-sectional length will directly lead to a reduction in the current-carrying area, resulting in a decrease in the current-carrying capacity of the connector 112, an increase in the internal resistance, and exacerbation of Joule heat loss and energy loss under high current conditions, making it unable to meet the high conductivity requirements of large-capacity cells. This lower limit ensures that the connector 112 has a basic current-carrying size, supports sufficient current-carrying capacity, and alleviates problems such as high internal resistance and severe overheating caused by an excessively small current-carrying cross-sectional size.

[0070] The upper limit of 0.25 defines the reasonable boundary for the extension of the connector 112. If the proportion exceeds this value, the excessive extension of the connector 112 in the length direction will encroach on the layout space of the explosion-proof valve and the electrolyte injection hole at the battery end. This will not only obstruct the electrolyte injection channel and affect the production electrolyte injection efficiency and electrolyte wetting effect, but also compress the venting and depressurization path and weaken the safety protection capability of the explosion-proof valve. At the same time, it will also cause material redundancy in the connector 112 and squeeze the space of the cell body 121, which will in turn reduce the battery capacity and energy density. This upper limit, while making full use of the space in the length direction of the battery to expand the current carrying capacity, reserves sufficient installation and operation space for the end functional structural components, ensuring the stable operation of core functions such as electrolyte injection and venting, while avoiding the space waste caused by structural redundancy.

[0071] In some embodiments where the minimum flow cross-section of the aforementioned intermediate connecting section is perpendicular to the second direction, the dimension of the connector 112 in the second direction is W2 mm, and the dimension of the battery in the second direction is W1 mm, wherein W2 and W1 satisfy: .

[0072] When the minimum current-carrying cross-section of the intermediate connecting section is perpendicular to the second direction, and the current is mainly conducted along the battery thickness direction, the higher the ratio of the dimension of the connector 112 in the second direction to the total dimension in the battery thickness direction, the longer the current-carrying path occupied by the connector 112 in the current-carrying path, and the better the overall current-carrying effect. However, the total space in the battery thickness direction is limited, and both assembly feasibility and the current-carrying path of the tab 122 must be considered simultaneously. This ratio... The value is limited to the range of 0.55-0.85, representing a synergistic optimization of current carrying capacity, assembly process, and overall performance of the conductive path. For example, this ratio can be any value between 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.2, 0.21, 0.22, 0.23, 0.24, 0.25, or 0.05-0.25.

[0073] The lower limit of 0.55 defines the minimum thickness ratio of the connector 112. If the ratio is lower than this value, the connector 112 will not account for enough of the current path, and the tab 122 will occupy a larger proportion of the current path. The tab 122 has a small overall thickness after being gathered together, and its current carrying capacity is significantly weaker than that of the connector 112. This will make the tab 122 the current bottleneck of the entire conductive circuit, increase the overall internal resistance of conductivity, increase the Joule heat loss under high current, and directly affect the energy retention rate of the battery.

[0074] The upper limit of 0.85 defines the reasonable boundary for the thickness extension of the connector 112. If the proportion exceeds this value, the excessive extension of the connector 112 in the thickness direction will squeeze the assembly gap, insulation buffer space and surrounding structure layout space inside the battery, greatly increasing the assembly difficulty of the cell assembly 120 and the connector 112, and even causing the risk of insulation failure. At the same time, it will also cause material redundancy in the connector 112, squeezing the available thickness space of the cell body 121, and conversely reducing the battery capacity and energy density.

[0075] In some embodiments where the minimum flow cross-section of the aforementioned intermediate connecting section is perpendicular to the second direction, the dimension of the connector 112 in the third direction is W mm, and the dimension of the battery in the third direction is H1 mm, where W and H1 satisfy: .

[0076] ratio This indicates the proportion of the connector 112 thickness in the total height space of the battery. This proportion cannot be too large or too small. If the proportion is too large, the connector 112 will occupy too much of the internal height space of the battery, compressing the assembly volume of the cell body and directly reducing the energy density of the battery. If the proportion is too small, since the larger the battery height corresponds to the higher cell capacity and the stronger the charging and discharging current demand, the thin connector 112 will have insufficient overcurrent cross-sectional area, resulting in increased conductivity resistance and Joule heat loss. This will make it unable to match the overcurrent demand of large-capacity cells, ultimately affecting the battery's energy retention rate.

[0077] Will Within the range of 0.0035-0.013, both current-carrying capacity and space utilization can be improved. For example, the ratio... The value can be any value between 0.0035, 0.004, 0.0045, 0.005, 0.0055, 0.006, 0.0065, 0.007, 0.0075, 0.008, 0.0085, 0.009, 0.0095, 0.01, 0.013, or 0.0035-0.013. The upper limit of 0.013 limits the maximum space ratio of the connector 112 thickness. While meeting basic overcurrent requirements, it strictly controls the height space occupied by the connector, preventing excessive thickness of the connector 112 from encroaching on the cell space, ensuring sufficient volume for the cell body, maintaining the battery's capacity and volumetric energy density, and avoiding material waste and energy density loss due to structural redundancy. The lower limit of 0.0035 limits the minimum thickness of the connector 112, preventing the connector 112 from becoming too thin and creating a conductivity bottleneck, thus ensuring the battery's energy conversion efficiency and energy retention rate.

[0078] In some embodiments where the minimum cross-sectional area of ​​the aforementioned intermediate connecting section is perpendicular to the second direction, the area of ​​the minimum cross-section of the conductive body 111 perpendicular to the third direction is S² mm. 2 S2 and S1 satisfy: .

[0079] In the battery's conductive circuit, current flows through connector 112 and into conductive body 111. The smallest cross-section of conductive body 111 perpendicular to a third direction is a critical overcurrent node on the conductive path of conductive body 111. The ratio of S2 to S1 reflects the matching degree of overcurrent capacity between conductive body 111 and connector 112. This ratio cannot be too large or too small. If the ratio is too large, the overcurrent capacity of conductive body 111 will be improved, but significant design redundancy will occur. Furthermore, an excessive increase in the minimum cross-section of conductive body 111 will simultaneously increase the overall volume and weight of conductive body 111, resulting in unnecessary consumption of conductive materials and an increase in battery weight. If the ratio is too small, the overcurrent capacity of conductive body 111 will not match that of connector 112. The minimum cross-section of conductive body 111 will become the overcurrent bottleneck of the entire conductive circuit, causing problems such as excessively high local current density, increased internal resistance, and aggravated Joule heat loss, ultimately leading to a low energy retention rate of the battery.

[0080] Limiting the ratio of S2 to S1 to the range of 1.5-6.5 can balance overcurrent matching and design redundancy. For example, the ratio of S2 to S1 can be 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5 or any value between 1.5 and 6.5.

[0081] The lower limit of 1.5 basically ensures that the cross-section of the conductive body 111 perpendicular to the third direction has sufficient current-carrying area, so that the current-carrying capacity of the conductive body 111 is compatible with the current-carrying capacity of the connector 112, preventing the conductive body 111 from becoming a short circuit in conductivity, eliminating the additional internal resistance and heat loss caused by an excessively small cross-sectional area, and ensuring the overall energy retention rate of the battery. The upper limit of 6.5 limits the upper limit of the minimum cross-sectional area of ​​the conductive body 111, avoiding excessive redundancy in the volume and weight of the conductive body 111 while meeting the current-carrying requirements of the conductive body 111, and controlling material consumption and battery weight.

[0082] In some embodiments where the aforementioned conductive body 111 is located outside the area directly opposite the two tabs 122 corresponding to the two cell assemblies 120, a plane perpendicular to a third direction is defined as the reference plane, and the cell assembly 120 forms a solder mark 1221 with the first connecting segment; the orthographic projection of the solder mark 1221 on the reference plane is the first projection; the projection of the area where the second connecting segment is connected to the conductive body 111 on the reference plane is the second projection; along the second direction, the first projection and the second projection do not overlap; the maximum dimension of the minimum current-carrying cross section of the intermediate connecting segment in the second direction is L mm, and the dimension of the battery in the second direction is W1 mm, where L and W1 satisfy: .

[0083] In embodiments where the conductive body 111 is located outside the area directly opposite the two tabs 122 corresponding to the two cell assemblies 120, the solder mark 1221 has two edges facing away from each other along a first direction. Along the first direction, the orthographic projection of the conductive body 111 onto the connector 112 is located on the side where one edge faces away from the other. During the process of the current flowing into the conductive body 111 through the solder mark 1221 and being guided from the connector 112 to the conductive body 111, the current direction is parallel to the first direction, i.e., parallel to the length direction of the battery. At this time, the minimum current-carrying cross-section of the intermediate connection section is perpendicular to the first direction. The dimension of the minimum current-carrying cross-section of the intermediate connection section in the direction perpendicular to the axial direction of the conductive body 111 can be understood as the maximum dimension of the minimum current-carrying cross-section along a second direction. For example, the minimum current-carrying cross-section of the intermediate connection section is rectangular or quasi-rectangular. The maximum dimension of the minimum current-carrying cross-section in the second direction can be understood as the length direction of the minimum current-carrying cross-section. In such embodiments, the length direction of the minimum current-carrying cross-section is consistent with the width direction of the battery.

[0084] When the length direction of the minimum current-carrying cross section of the intermediate connection section is consistent with the width direction of the battery, This directly reflects the proportion of space occupied by the connector 112 in the width direction of the battery. This ratio cannot be too large or too small. If the ratio is too large, the edge of the connector 112 will be too close to the edge of the cover plate 131, encroaching on the assembly positioning allowance and welding space of the cover plate 131 and the housing 132. This can easily cause assembly misalignment and insufficient effective weld width, thereby affecting the sealing performance and structural connection reliability of the housing 132 and increasing the production defect rate. If the ratio is too small, the length of the minimum current-carrying cross-section of the intermediate connection section will be insufficient, directly resulting in insufficient current-carrying cross-sectional area. This reduces the current-carrying capacity of the connector, increases the internal resistance of conductivity, and cannot match the high current conduction requirements of large-capacity cells, exacerbating Joule heat loss and ultimately reducing the energy retention rate of the battery.

[0085] In this embodiment, the ratio of the maximum dimension L of the minimum current-carrying cross section along the second direction to the dimension W1 of the battery in the second direction is limited to between 0.6 and 0.95, which achieves a synergistic balance between current-carrying capacity and assembly manufacturability. For example, this ratio can be any value between 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, or 0.6-0.95.

[0086] The lower limit of 0.6 defines the minimum size threshold of connector 112 along the width direction of the battery, ensuring that connector 112 has sufficient cross-sectional area to carry the working current of large-capacity cells, avoiding problems such as high internal resistance and severe overheating caused by insufficient cross-sectional size, and ensuring basic overcurrent performance and energy conversion efficiency. The upper limit of 0.95 defines the maximum size threshold of connector 112 along the width direction of the battery. While making full use of the space in the width direction of the battery to expand the overcurrent capacity, it also reserves sufficient process safety margin for the assembly alignment and circumferential welding of cover plate 131 and shell 132, avoiding interference of the base plate on the assembly and welding process, ensuring the sealing performance and structural connection strength of shell 132, and also avoiding material waste and internal space encroachment caused by excessive redundancy in the size of connector 112.

[0087] In some embodiments, S1, L, and W satisfy the following: .

[0088] In some embodiments of this application, the minimum flow cross section of the intermediate connecting section of the connector 112 is rectangular, and the area of ​​the minimum flow cross section is the product of the thickness of the connector 112 and the length of the connector 112.

[0089] In some embodiments, L satisfies: 20 ≤ L ≤ 80. For example, L can be 20, 21, 25, 28, 30, 34, 35, 40, 41, 45, 46, 50, 51, 55, 60, 65, 70, 80 or any value between 20 and 80.

[0090] In some embodiments, W satisfies: 0.6 ≤ W ≤ 4. For example, W can be any value between 0.6, 0.8, 1, 1.2, 1.5, 1.8, 2, 2.2, 2.5, 3, 4, or 0.6-4.

[0091] The following uses 10 examples to test the battery capacity retention rate of the battery in this application, and compares the results with 7 comparative examples. The positive electrode active material of the batteries in these 10 examples and 7 comparative examples all includes lithium iron phosphate (LFP), and the minimum current-carrying cross-section of the connector is rectangular. The area of ​​the minimum current-carrying cross-section of the connector is the product of the thickness and length of the connector, which satisfies... The specific test results are shown in Tables 1 and 2. For ease of explanation, some data recorded in Tables 1 and 2 are rounded, and all data before processing meet the limitations of this application. As can be seen from Tables 1 and 2, the structural design of the connector in the battery provided in the embodiments of this application can better ensure the overcurrent capacity of large-capacity cells while reducing the amount of connectors used to a certain extent, reducing space occupation and cost, and improving battery round-trip efficiency.

[0092] Table 1. Record of Battery Capacity Retention Rate Test Results for Lithium Iron Phosphate Batteries (Table 1)

[0093] Table 2. Record of Battery Capacity Retention Rate Test Results for Lithium Iron Phosphate Batteries (Table 2)

[0094] The following describes battery capacity retention tests using seven embodiments as examples, and comparative tests are conducted using six comparative examples. In all seven embodiments and six comparative examples, the positive electrode active material of the battery includes lithium manganese iron phosphate (LMFP), and the minimum current-carrying cross-section of the connector is rectangular. The minimum current-carrying cross-sectional area of ​​the connector is the product of the connector's thickness and length, which satisfies... The specific test results are shown in Tables 3 and 4. For ease of explanation, some data in Tables 3 and 4 are rounded, and all data before processing still meet the requirements of this application. As can be seen from Tables 3 and 4, the structural design of the connectors in the battery provided in this application embodiment can better ensure the overcurrent capacity of large-capacity cells while reducing the amount of connectors used to a certain extent, reducing space occupation and cost, and improving battery round-trip efficiency.

[0095] Table 3. Record of Battery Capacity Retention Rate Test Results for Lithium Manganese Iron Phosphate Batteries (Table 1)

[0096] Table 4. Record of Battery Capacity Retention Rate Test Results for Lithium Manganese Iron Phosphate Batteries (Table 2)

[0097] Obviously, those skilled in the art can make various modifications and variations to the embodiments of this application without departing from the spirit and scope of this application. Therefore, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application also intends to include these modifications and variations.

Claims

1. A battery, characterized in that, It includes a terminal assembly and a cell assembly; the cell assembly is electrically connected to the terminal assembly; the terminal assembly includes a conductive body and a connector, and the cell assembly is electrically connected to the conductive body through the connector; The connector includes a first connecting segment, a second connecting segment, and an intermediate connecting segment. The first connecting segment is connected to the battery cell assembly, and the second connecting segment is connected to the conductive body. The intermediate connecting segment connects the first connecting segment and the second connecting segment. The battery satisfies: ； Wherein: the battery capacity is C Ah, and C≥314; the battery charge / discharge power is AW; the battery system coefficient is K, and K is the ratio of the plateau voltage to the terminal voltage in the battery; the minimum current-carrying cross-sectional area of ​​the intermediate connecting section of the connector is S1 mm. 2 .

2. The battery according to claim 1, characterized in that, The positive electrode active material of the battery includes lithium manganese iron phosphate, and the battery satisfies the following: 。 3. The battery according to claim 1, characterized in that, The positive electrode active material of the battery includes lithium iron phosphate, and the battery satisfies the following conditions: 。 4. The battery according to claim 1 or 3, characterized in that, The condition C satisfies: 314≤C≤3000.

5. The battery according to claim 1, characterized in that, The ratio of the battery capacity to the battery volume is VED kWh / L, and VED satisfies: 300≤VED≤800.

6. The battery according to claim 1, characterized in that, The battery also includes a cover plate, and the terminal assembly is disposed on the cover plate; the size of the battery in a first direction is larger than the size of the battery in a second direction, and the first direction, the second direction, and the third direction are perpendicular to each other; the third direction is the arrangement direction of the cover plate and the cell assembly; A plane perpendicular to the third direction is defined as a reference plane, and the cell assembly forms a solder mark with the first connecting segment; The orthographic projection of the solder mark on the reference plane is the first projection; the projection of the area where the second connecting segment is connected to the conductive body on the reference plane is the second projection; along the second direction, the first projection and the second projection at least partially overlap. The maximum dimension of the minimum current-carrying cross section of the intermediate connecting section in the first direction is L mm, and the dimension of the battery in the first direction is L1 mm. L and L1 satisfy the following: 。 7. The battery according to claim 6, characterized in that, The dimension of the connector in the second direction is W2 mm, and the dimension of the battery in the second direction is W1 mm. W2 and W1 satisfy the following: 。 8. The battery according to claim 6, characterized in that, The dimension of the connector in the third direction is W mm, and the dimension of the battery in the third direction is H1 mm. W and H1 satisfy the following: 。 9. The battery according to any one of claims 6-8, characterized in that, The area of ​​the smallest cross-section of the conductive body perpendicular to the third direction is S² mm. 2 S2 and S1 satisfy: 。 10. The battery according to claim 1, characterized in that, The battery also includes a cover plate, and the terminal assembly is disposed on the cover plate; the size of the battery in a first direction is larger than the size of the battery in a second direction, and the first direction, the second direction, and the third direction are perpendicular to each other; the third direction is the arrangement direction of the cover plate and the cell assembly; A plane perpendicular to the third direction is defined as a reference plane, and the cell assembly forms a solder mark with the first connecting segment; The orthographic projection of the solder mark on the reference plane is the first projection; the projection of the area where the second connecting segment is connected to the conductive body on the reference plane is the second projection; along the second direction, the first projection and the second projection do not overlap; The minimum current-carrying cross-section of the intermediate connecting section has a maximum dimension of L mm in the second direction, and the battery has a dimension of W1 mm ​​in the first direction. L and W1 satisfy the following: 。

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