Battery, battery device, and electric device

Abstract

The application provides a battery, a battery device and a power utilization equipment, relates to the technical field of batteries, and comprises a shell and a battery core. The shell is provided with a pressure relief part which is opened to form a pressure relief opening under a preset condition; the area of the pressure relief part is S, the unit of S is mm 2 ; the battery core is arranged in the shell, the capacity of the battery is A, and the unit of A is Ah. The shell is filled with an electrolyte, the electrolyte comprises lithium hexafluorophosphate and lithium bisfluorosulfonylimide, the concentration of lithium hexafluorophosphate is mu, and the unit of mu is mol / L; the concentration of lithium bisfluorosulfonylimide is lambda, and the unit of lambda is mol / L. S, A, mu and lambda satisfy: S / A >= 0.5*mu / lambda. Through the arrangement, the safety of the battery is improved.

Description

Technical Field

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

[0002] With the continuous development of battery technology, the electrical performance of batteries is constantly improving, which also puts forward higher requirements for battery safety.

[0003] In related technologies, a battery includes a casing, a cell, and an electrolyte, with the cell and electrolyte both housed within the casing. The casing has an openable pressure relief structure. When thermal runaway occurs in the cell, the pressure relief structure opens to reduce the pressure inside the casing, thereby preventing the battery from exploding. However, batteries in these technologies suffer from a mismatch between the pressure relief structure and the gas generation rate inside the battery, leading to a decrease in battery safety. Summary of the Invention

[0004] This application provides a battery, a battery device, and an electrical appliance that can at least solve the technical problem of deteriorated battery safety caused by the mismatch between the pressure relief structure and the gas generation rate inside the battery.

[0005] To achieve the above objectives, this application adopts the following technical solution:

[0006] In a first aspect, this application provides a battery, comprising:

[0007] The housing includes a pressure relief section that opens under preset conditions; the area of ​​the pressure relief section is S, where S is in mm. 2 .

[0008] The battery cell is disposed within the housing.

[0009] The battery has a capacity of A, and the unit of A is Ah.

[0010] The shell is filled with an electrolyte comprising lithium hexafluorophosphate and lithium bis(fluorosulfonyl)imide. The concentration of lithium hexafluorophosphate is μ, where μ is in mol / L; and the concentration of lithium bis(fluorosulfonyl)imide is λ, where λ is in mol / L.

[0011] Wherein, S, A, μ, and λ satisfy: .

[0012] As an optional implementation, S, A, μ, and λ satisfy: .

[0013] As an optional implementation, A satisfies: 50 ≤ A ≤ 500.

[0014] As an optional implementation, A satisfies: 50 ≤ A ≤ 250.

[0015] As an optional implementation, μ satisfies: 0.5 ≤ μ ≤ 1.2.

[0016] As an optional implementation, μ satisfies: 0.6 ≤ μ ≤ 1.0.

[0017] As an optional implementation, λ satisfies: 0 ≤ λ ≤ 0.6.

[0018] As an optional implementation, λ satisfies: 0.1≤λ≤0.4.

[0019] As an optional implementation, the number of pressure relief sections is n, where n ≥ 1; and S satisfies: .

[0020] As an alternative implementation, the housing includes grooves for forming the pressure relief section.

[0021] And / or, the housing includes a thinning region for forming the pressure relief section.

[0022] As an optional implementation, the notch is an open annular structure or a closed annular structure, and S is the area enclosed by the open annular structure or the closed annular structure.

[0023] As an optional implementation, there are multiple grooves, which are arranged in a radial structure and intersect at the radial center of the radial structure. S is the area enclosed by the lines connecting the free ends of the multiple grooves.

[0024] As an optional implementation, the housing also includes an explosion-proof valve, which is provided with the grooves and / or the thinning area.

[0025] In a second aspect, this application provides a battery device comprising: a battery as described in the first aspect.

[0026] Thirdly, this application provides an electrical device, including: a battery as described in the first aspect; or a battery device as described in the second aspect.

[0027] The battery, battery device, and electrical equipment provided in this application can adjust the structure of the pressure relief section by setting the parameter relationship between the battery capacity, the concentration of lithium hexafluorophosphate and lithium difluorosulfonylimide in the electrolyte, and the area of ​​the pressure relief section. This ensures that the pressure relief section can adapt to different gas production rates of the battery, thereby quickly releasing the internal pressure of the casing, avoiding the explosion hazard caused by the increase of pressure inside the casing, and thus improving the safety of the battery.

[0028] In addition to the technical problems solved by this application, the technical features constituting the technical solutions, and the beneficial effects brought about by the technical features of these technical solutions as described above, other technical problems that can be solved by the batteries, battery devices, and electrical equipment provided by this application, other technical features contained in the technical solutions, and the beneficial effects brought about by these technical features will be further explained in detail in the specific embodiments. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 A schematic diagram of a battery provided in an embodiment of this application;

[0031] Figure 2 for Figure 1 A schematic diagram of the battery from another perspective;

[0032] Figure 3 This is a schematic diagram of a pressure relief section in a battery provided in an embodiment of this application;

[0033] Figure 4 This is a schematic diagram of another pressure relief section in a battery provided in an embodiment of this application;

[0034] Figure 5 A schematic diagram of another pressure relief section in a battery provided in an embodiment of this application;

[0035] Figure 6 This is a schematic diagram of another pressure relief section in a battery provided in an embodiment of this application.

[0036] Explanation of reference numerals in the attached figures:

[0037] 100-battery;

[0038] 110 - Housing; 111 - Pressure relief section; 1111 - Score;

[0039] 120-cell;

[0040] 130 - Explosion-proof valve. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, 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, not all embodiments. Based on the embodiments of this application, other embodiments obtained by those skilled in the art without creative effort are all within the scope of protection of this application. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0042] The contents of this application will now be described in detail with reference to the accompanying drawings, so that those skilled in the art can have a clearer and more detailed understanding of the contents of this application.

[0043] See Figure 1 and Figure 2 This application provides a battery 100, including a casing 110 and a battery cell 120.

[0044] The housing 110 is provided with a pressure relief section 111, which opens under preset conditions. The area of ​​the pressure relief section 111 is S, where S is in mm. 2 The battery cell 120 is located inside the casing 110; the battery capacity of the battery 100 is A, and the unit of A is Ah.

[0045] The casing 110 is filled with an electrolyte, which includes lithium hexafluorophosphate and lithium bis(fluorosulfonyl)imide. The concentration of lithium hexafluorophosphate is μ, where μ is in mol / L; the concentration of lithium bis(fluorosulfonyl)imide is λ, where λ is in mol / L.

[0046] Where S, A, μ and λ satisfy: .

[0047] Understandably, the pressure relief section 111 in this embodiment forms a through-connection structure after opening under preset conditions, thereby connecting the inside and outside of the housing 110 and releasing the internal pressure of the housing 110. The preset condition is the pressure at which gas forms inside the housing 110 after the battery cell 120 thermally runs away, and the pressure increases to force the pressure relief section 111 open.

[0048] In the event of thermal runaway in cell 120, the gas production rate of battery 100 is related to the capacity A (unit: Ah) of battery 100, the concentration μ (unit: mol / L) of lithium hexafluorophosphate (LiPF6), and the concentration λ (mol / L) of lithium bisfluorosulfonylimide (LiFSI).

[0049] To facilitate understanding of the embodiments of this application by those skilled in the art, definitions are provided. That is to say, α≤0.65, and α can be: 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, etc. Any value that meets the above range is acceptable, and this embodiment does not require it.

[0050] When α > 0.65, after thermal runaway of cell 120, pressure relief section 111 opens. The area of ​​pressure relief section 111 is not compatible with the gas production rate. After pressure relief section 111 opens, poor gas exhaust will occur, and even fire may occur inside the casing 110 of battery 100, and the internal pressure of casing 110 may increase suddenly, causing an explosion.

[0051] Thus, by setting the parameter relationship between the capacity of the battery 100, the concentration of lithium hexafluorophosphate (LiPF6) and lithium bisfluorosulfonylimide (LiFSI) in the electrolyte and the area of ​​the pressure relief section 111, the structure of the pressure relief section 111 can be adjusted to ensure that the pressure relief section 111 can adapt to different gas production rates of the battery 100 after being opened under preset conditions, thereby quickly releasing the internal pressure of the casing 110, avoiding the explosion hazard caused by the increase in pressure inside the casing 110, and thus improving the safety of the battery 100.

[0052] As an optional implementation, S, A, μ, and λ in this embodiment satisfy: .

[0053] In this embodiment, by setting α≤0.5, it can be further ensured that the area of ​​the pressure relief section 111 is adapted to the gas generation rate. When the cell 120 thermally runs away, the pressure relief section 111 opens and forms a pressure relief port on the housing 110. The gas inside the housing 110 is quickly discharged through the pressure relief port to quickly reduce the internal pressure of the housing 110, thereby avoiding the situation where the battery 100 explodes due to the high internal pressure of the housing 110, thus improving the safety of the battery 100.

[0054] For example, α in this embodiment can be: 0.03, 0.1, 0.12, 0.15, 0.17, 0.18, 0.2, 0.23, 0.25, 0.26, 0.28, 0.29, 0.3, 0.32, 0.34, 0.385, 0.39, 0.4, 0.45, 0.5, etc. Any value within the above range is acceptable, and this embodiment does not impose specific requirements on it.

[0055] As an optional implementation, in this embodiment, A satisfies: 50 ≤ A ≤ 500. Here, the unit of A is Ah.

[0056] For example, A in this embodiment can be: 50, 80, 100, 120, 150, 180, 200, 210, 230, 250, 280, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, 410, 420, 430, 440, 450, 460, 470, 480, 490, 500, etc., and any value within the above range is acceptable; this embodiment does not require it. It should be noted that in this embodiment, A can still ensure that α satisfies: α≤0.65, or α≤0.5, thereby adjusting the gas generation rate to ensure the safety of battery 100. Furthermore, by setting A, the structure of the pressure relief section 111 is improved to ensure the area of ​​the pressure relief section 111, so that the pressure relief port formed by opening the pressure relief section 111 can adapt to different gas production rates, ensuring smooth exhaust when the cell 120 experiences thermal runaway, so as to achieve the purpose of rapid pressure relief and thereby improve the safety of the battery 100.

[0057] As an optional implementation, A satisfies: 50 ≤ A ≤ 250.

[0058] For example, A in this embodiment can be: 50, 70, 85, 90, 100, 120, 140, 150, 180, 200, 210, 230, 250, etc., and any value within the above range is acceptable; this embodiment does not require it. It should be noted that A in this embodiment can still satisfy α ≤ 0.65, or α ≤ 0.5, thereby adjusting the gas generation rate and better ensuring the safety of battery 100. Simultaneously, through the above settings, the area of ​​the pressure relief section 111 can be determined, allowing for the design of the structure of the pressure relief section 111. This ensures that battery 100 can quickly and smoothly release gas during thermal runaway of cell 120, preventing battery 100 from exploding and thus improving the safety of battery 100.

[0059] As an optional implementation, μ in this embodiment satisfies: 0.5 ≤ μ ≤ 1.2.

[0060] Specifically, μ can be 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, etc., and any value within the above range is acceptable; this embodiment does not require it. It should be noted that in this embodiment, μ can ensure that α satisfies: α≤0.65, or α≤0.5, thereby adjusting the gas generation rate and better ensuring the safety of battery 100.

[0061] During the design of battery 100, the area of ​​the corresponding pressure relief part 111 can be determined according to μ, so as to design the structure of the pressure relief part 111. When the cell 120 thermally runs away, the battery 100 can quickly open and form a pressure relief port to quickly reduce the internal pressure of the casing 110, prevent the battery 100 from exploding, and thus improve the safety of the battery 100.

[0062] Furthermore, in this embodiment, μ satisfies: 0.6 ≤ μ ≤ 1.0. This embodiment, by setting μ, more stably ensures the safety of battery 100.

[0063] For example, μ can be: 0.6, 0.62, 0.65, 0.68, 0.7, 0.71, 0.73, 0.78, 0.79, 0.8, 0.83, 0.84, 0.85, 0.89, 0.9, 0.92, 0.94, 0.96, 0.99, 1.0, etc., and any value within the above range is acceptable; this embodiment does not require it. It should be noted that in this embodiment, μ can ensure that α satisfies: α≤0.65, or α≤0.5, thereby controlling the gas generation rate and better ensuring the safety of battery 100.

[0064] In this embodiment of the application, by setting μ, the area of ​​the pressure relief part 111 can be determined so as to design the structure of the pressure relief part 111, thereby ensuring that the battery 100 can quickly and smoothly release gas when the cell 120 thermally runs away, avoiding the occurrence of battery 100 explosion, and thus improving the safety of battery 100.

[0065] Optionally, in this embodiment, λ satisfies: 0≤λ≤0.6.

[0066] For example, λ can be 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, etc., and any value within the above range is acceptable. This embodiment does not make specific requirements in this regard.

[0067] It should be noted that when λ is 0, there is no lithium bisfluorosulfonylimide in the electrolyte. In this embodiment, the setting of λ still ensures that α satisfies: α≤0.65, or α≤0.5, and can appropriately control the gas generation rate of the battery 100 during thermal runaway of the cell 120. Furthermore, by setting λ, the area of ​​the pressure relief section 111 can be determined, and the structure of the pressure relief section 111 can be designed to ensure that the battery 100 can quickly and smoothly vent gas during thermal runaway of the cell 120, avoiding the occurrence of battery 100 explosion, thereby improving the safety of the battery 100.

[0068] In some embodiments, λ satisfies: 0.1≤λ≤0.4.

[0069] Specifically, in this embodiment, λ can be 0.1, 0.12, 0.13, 0.15, 0.17, 0.19, 0.2, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.3, 0.33, 0.34, 0.38, 0.9, 0.4, etc. Any value within the above range is acceptable, and this embodiment does not impose any restrictions on it.

[0070] Understandably, the gas production rate of battery 100 after thermal runaway of cell 120 will also be different when λ is different. Through the above settings, the gas production rate of battery 100 can be changed synchronously. And through the structural design of pressure relief part 111, it is ensured that the pressure relief port formed after pressure relief part 111 is opened is adapted to the gas production rate, so as to quickly and smoothly exhaust gas and complete the pressure relief of battery 100, thereby avoiding the explosion of battery 100 and improving the safety of battery 100.

[0071] In conjunction with the foregoing embodiments, those skilled in the art will understand that the number of pressure relief sections 111 is n, where n ≥ 1; and S satisfies: .

[0072] To facilitate understanding of this embodiment by those skilled in the art, this section uses n=4 as an example for explanation. The four pressure relief sections are defined as the first pressure relief section, the second pressure relief section, the third pressure relief section, and the fourth pressure relief section.

[0073] The area of ​​the first pressure relief section is S1, the area of ​​the second pressure relief section is S2, the area of ​​the third pressure relief section is S3, and the area of ​​the fourth pressure relief section is S4. The area of ​​the pressure relief section 111 is S = S1 + S2 + S3 + S4.

[0074] It should be noted that after the pressure relief section 111 is opened, this embodiment does not require the specific location of the multiple pressure relief ports formed by the pressure relief section 111.

[0075] As an optional implementation, the pressure relief part 111 can be an opening provided on the housing 110, and the opening can be closed by a cover plate detachably connected to the housing 110. The cover plate can be opened under preset conditions.

[0076] Optional, see Figures 3 to 6 The housing 110 includes a groove 1111, which forms a pressure relief portion 111. Alternatively, the housing 110 includes a thinning region, which forms a pressure relief portion 111.

[0077] It should be noted that the notch 1111 in this embodiment can be provided on the shell wall of the housing 110. By providing the notch 1111, the thickness of the shell wall of the housing 110 is reduced at the notch 1111, so that the shell wall of the housing 110 can open under preset conditions, thereby forming a pressure relief port. In addition, the thinning area in this embodiment is formed by reducing the thickness of part of the shell wall of the housing 110.

[0078] As an optional implementation, the housing 110 also includes an explosion-proof valve 130, which has grooves 1111 and / or a thinning region. By providing grooves 1111 on the explosion-proof valve 130, the grooves 1111 on the explosion-proof valve 130 open under preset conditions to form a pressure relief port. The thickness of the valve wall of the explosion-proof valve 130 is reduced to form a thinning region, which opens under preset conditions to form a pressure relief port.

[0079] Optional, see Figure 3 and Figure 4 The notch 1111 is an open or closed ring structure. S is the area enclosed by the open or closed ring structure.

[0080] See Figure 3 and Figure 4 It can be understood that the open-loop structure and the line connecting the two ends of the open-loop structure ( Figure 3 The dotted lines in the middle Figure 4 The area enclosed by the dashed line in the figure is the area S of the pressure relief part 111 in this embodiment.

[0081] When there are multiple notches 1111, all notches 1111 can be open annular structures, or all notches 1111 can be closed annular structures, or a portion of the notches 1111 can be open annular structures, while the remaining notches 1111 can be closed annular structures. By setting the notches 1111 with open annular structures and / or closed annular structures, the length of the notches 1111 is increased, allowing multiple positions of the notches 1111 to be opened, thereby improving the safety of the battery 100.

[0082] See Figure 5 In this embodiment, there are multiple notches 1111, which are arranged in a radial structure and intersect at the radial center. S is the area enclosed by the lines connecting the free ends of the multiple notches 1111. Figure 5 (The area enclosed by the dashed line). It should be noted that the free end of the notch 1111 is the end of the notch 1111 that is away from the radial center of the radial structure.

[0083] Thus, the slit-like pressure relief port formed by the tearing of the notch 1111, or the tearing of the notch 1111 and the wall of the explosion-proof valve 130 and / or the shell wall of the housing 110 folding outward under the action of the internal pressure of the housing 110, to form a pressure relief port.

[0084] See Figure 6 In this embodiment, the pressure relief section 111 includes a closed annular structure with grooves 1111 and radial grooves 1111. When the grooves 1111 are torn, they can form a pressure relief port at the closed annular structure or at the radial grooves 1111. It should be noted that in this embodiment, S represents the area of ​​the region enclosed by the closed annular structure.

[0085] Secondly, embodiments of this application provide a battery device, including the battery 100 described in the first aspect.

[0086] For example, the battery device can be a battery pack, battery module, chassis (such as a CTC integrated chassis, skateboard chassis, etc.), energy storage box, power bank, etc., and this embodiment does not limit it.

[0087] In some embodiments, the battery pack includes a plurality of batteries 100, which may be stacked or disposed within a housing.

[0088] In some embodiments, the battery pack includes a pack body, and a plurality of batteries 100 or a battery pack are disposed within the pack body.

[0089] In some embodiments, the chassis includes a frame, within which multiple batteries 100 or battery packs or battery stacks are disposed. The number of batteries 100 can be multiple, and the number of battery packs can be multiple.

[0090] When there are multiple batteries 100, the multiple batteries 100 can be arranged in a horizontal and / or vertical direction. When there are multiple battery packs, the multiple battery packs can be arranged in a horizontal and / or vertical direction.

[0091] The battery device in this embodiment includes the battery 100 from the aforementioned embodiments, which can improve the safety of the battery device.

[0092] Thirdly, embodiments of this application provide an electrical device, including: the battery 100 provided in the first aspect, or the battery device provided in the second aspect.

[0093] For example, the electrical equipment in this embodiment can be a vehicle, mobile phone, computer, aircraft, etc. When the electrical equipment is a vehicle, the vehicle can be a fuel vehicle, hybrid vehicle, pure electric vehicle, etc.

[0094] The electrical equipment in this embodiment includes the battery 100 mentioned in the first aspect or the battery device mentioned in the second aspect, which can improve the safety of the electrical equipment.

[0095] The battery 100 provided in this application will be further described below with reference to specific embodiments. The example given is that the pressure relief section 111 is located in the explosion-proof valve 130.

[0096] Example 1: The capacitance A of cell 120 is 203.8, the LiPF6 concentration μ is 0.660, the LiFSI concentration λ is 0.13, the number of positive electrode layers in cell 120 is 60, the number of negative electrode layers in cell 120 is 61, and the explosion-proof valve 130 is designed with dimensions of 10mm × 30mm. After thermal runaway of cell 120, the area S of the pressure relief port is 178.5, and α = 0.36.

[0097] Example 2: The capacitance A of cell 120 is 208.0, the LiPF6 concentration μ is 0.890, the LiFSI concentration λ is 0.130, the positive electrode layer in cell 120 has 52 layers, the negative electrode layer in cell 120 has 53 layers, and the explosion-proof valve 130 has a design size of 10mm × 30mm. After thermal runaway of cell 120, the area S of the pressure relief port is 178.5, and α = 0.40.

[0098] Example 3: The capacitance A of cell 120 is 214.6, the LiPF6 concentration μ is 0.780, the LiFSI concentration λ is 0.230, the positive electrode layer in cell 120 has 47 layers, the negative electrode layer in cell 120 has 48 layers, and the explosion-proof valve 130 has dimensions of 10mm × 30mm. After thermal runaway of cell 120, the area S of the pressure relief port is 178.5, and α = 0.44.

[0099] Example 4: The capacitance A of cell 120 is 78.5, the LiPF6 concentration μ is 0.660, the LiFSI concentration λ is 0.130, the positive electrode layer in cell 120 has 36 layers, the negative electrode layer in cell 120 has 37 layers, and the explosion-proof valve 130 has a design size of 10mm × 20mm. After thermal runaway of cell 120, the area S of the pressure relief port is 108.5, and α = 0.49.

[0100] Example 5: The capacitance A of cell 120 is 84.5, the LiPF6 concentration μ is 0.562, the LiFSI concentration λ is 0.241, the positive electrode layer in cell 120 has 34 layers, the negative electrode layer in cell 120 has 35 layers, and the explosion-proof valve 130 has a design size of 10mm × 20mm. After thermal runaway of cell 120, the area S of the pressure relief port is 108.5mm². 2 , α=0.56.

[0101] Example 6: The capacity A of cell 120 is 150.0 Ah, the LiPF6 concentration μ is 0.618, the LiFSI concentration λ is 0.200, the positive electrode layer in cell 120 has 34 layers, the negative electrode layer in cell 120 has 35 layers, and the explosion-proof valve 130 has a design size of 10mm × 20mm. After thermal runaway of cell 120, the area S of the pressure relief port is 108.5, and α = 0.61.

[0102] Example 7: The capacitance A of cell 120 is 119.0, the LiPF6 concentration μ is 0.770, the LiFSI concentration λ is 0.250, the positive electrode layer in cell 120 has 52 layers, the negative electrode layer in cell 120 has 53 layers, and the explosion-proof valve 130 has a design size of 10mm × 20mm. After thermal runaway of cell 120, the area S of the pressure relief port is 108.5, and α = 0.65.

[0103] Example 8: The capacitance A of cell 120 is 124.6, the LiPF6 concentration μ is 0.800, the LiFSI concentration λ is 0.130, the positive electrode layer in cell 120 has 32 layers, the negative electrode layer in cell 120 has 33 layers, and the explosion-proof valve 130 has a design size of 10mm × 20mm. After thermal runaway of cell 120, the area S of the pressure relief port is 108.5, and α = 0.56.

[0104] Example 9: The capacitance A of cell 120 is 158.2, the LiPF6 concentration μ is 0.820, the LiFSI concentration λ is 0.130, the positive electrode layer in cell 120 has 44 layers, the negative electrode layer in cell 120 has 45 layers, and the explosion-proof valve 130 has a design size of 10mm × 20mm. After thermal runaway of cell 120, the area S of the pressure relief port is 108.5, and α = 0.60.

[0105] Comparative Example 1: The capacitance A of cell 120 is 124.6, the LiPF6 concentration μ is 0.600, the LiFSI concentration λ is 0.312, the positive electrode layer in cell 120 has 32 layers, the negative electrode layer has 33 layers, and the explosion-proof valve 130 has a design size of 10mm × 20mm. After thermal runaway of cell 120, the area S of the pressure relief port is 108.5, and α = 0.67 is calculated.

[0106] Comparative Example 2: Cell 120 has a capacitance A of 158.2, a LiPF6 concentration μ of 0.600, a LiFSI concentration λ of 0.350, 44 layers of positive electrode plates, and 45 layers of negative electrode plates. The explosion-proof valve 130 has a design size of 10mm × 20mm. After thermal runaway, the area S of the pressure relief port of cell 120 is 108.5, and α = 0.73.

[0107] The test standards for each parameter in the above embodiments and comparative examples are as follows:

[0108] 1. Capacity A of cell 120:

[0109] Condition ①: If the rated capacity of a 120mAh battery cell is known, then:

[0110] I1: 1 h-rate discharge current (A), the value of which is equal to the rated capacity value.

[0111] I3: 3 h-rate discharge current (A), the value of which is equal to 1 / 3 of the rated capacity value.

[0112] a) Standard charging: At room temperature, the test sample is first discharged with a current of 1 I3 until the battery voltage reaches 100 and the discharge cutoff voltage is reached. After resting for 30 minutes or the time specified by the manufacturer, the test sample is then charged with a current of 1 I3 until the single cell voltage reaches the charging cutoff voltage. Then, constant voltage charging is switched to constant voltage charging. Charging is stopped when the charging current drops to 0.05 I1. After charging, the sample is rested for 30 minutes or the specified time.

[0113] b) Standard discharge: At room temperature, the battery 100 is discharged at a constant current of 1 I3 until the single cell voltage reaches the discharge cutoff voltage, and then left to stand for 30 minutes or a specified time.

[0114] c) Repeat steps a) through b) a total of three times. Let Q be the value of each of the three discharges. 01 Q 02 and Q 03 Let Q0 be the arithmetic mean of the three discharges. If Q 01 Q 02 and Q 03 If the mutual deviation r < 3%, then Q0 is the capacity A of the battery 100; if r ≥ 3%, then the capacity test process needs to be repeated until the discharge amount of three consecutive times meets the confirmation condition of r < 3%.

[0115] d)Q 01 Q 02 and Q 03 The mutual deviation r is calculated as shown in equation (1):

[0116] r =(Q max -Q min ) / Q min ×100% (1)

[0117] In formula (1):

[0118] Q max : Maximum discharge capacity (Ah) after three discharges;

[0119] Q min Minimum discharge capacity (Ah) after three discharges.

[0120] Condition ②: If the rated capacity information of cell 120 is unknown, then:

[0121] a) At room temperature, the test sample is first discharged with a current of 10A until the battery voltage reaches 100V and the discharge cutoff voltage is reached. After resting for 30 minutes or a specified time, the test sample is then charged with a current of 10A until the single cell voltage reaches the charging cutoff voltage. After charging, it is rested for 30 minutes or a specified time.

[0122] b) Standard discharge: At room temperature, the battery 100 is discharged at a constant current of 10A until the single cell voltage reaches the discharge cutoff voltage, and then left to stand for 30 minutes or a specified time.

[0123] Repeat steps a) through b) a total of three times. Let Q be the value of each discharge. 01 Q 02 and Q 03 Let Q0 be the arithmetic mean of the three discharges. If Q 01 Q 02 and Q 03 If the mutual deviation r < 3%, then Q0 is the capacity A of the battery 100; if r ≥ 3%, then the capacity test process needs to be repeated until the discharge amount of three consecutive times meets the confirmation condition of r < 3%. Wherein, r is obtained by the above formula (1).

[0124] 2. Determination of LiPF6 concentration μ:

[0125] Prepare a 10 ml sample (V), weigh and record the sample weight (m), and determine the [PF6] in the electrolyte using ion chromatography (IC). - With [FSI] - The ppm values ​​are a and b, respectively. Another 1 ml sample of electrolyte is prepared. Gas chromatography (GC) is used to determine the ppm values ​​of other solvents, additives, and other components in the electrolyte, with set values ​​(c, d, e, etc.). The measured ppm values ​​(a, b, c, etc.) are summed to obtain H, from which [PF6] can be calculated. - With [FSI] - The quality fraction is [PF6]. - The formula for calculating the concentration μ is shown in equation (2):

[0126] (2)

[0127] Where M is the molar mass of LiPF6, M = 151.91 g / mol; μ is the concentration of LiPF6, in mol / L; and m is the mass of the electrolyte sample, in g.

[0128] a, b, c, etc. are [PF6] - With [FSI] -The percentage of solvents and additives in the electrolyte, in units of %.

[0129] 3. LiFSI concentration λ:

[0130] The method for measuring LiPF6 concentration μ is the same as that for [FSI]. - The formula for calculating the concentration λ is shown in equation (3):

[0131] (3)

[0132] Where M is the molar mass of LiFSI, M = 151.91 g / mol; λ is the concentration of LiFSI, in mol / L; and m is the mass of the electrolyte sample, in g.

[0133] a, b, c, etc. are [PF6] - With [FSI] - The percentage of solvents and additives in the electrolyte, in units of %.

[0134] 4. Localized heating test:

[0135] Testing requirements:

[0136] 1) Test equipment and samples: 100 batteries, charging equipment, heating film.

[0137] 2) Battery 100 does not have blue film.

[0138] Pre-treatment of battery 100:

[0139] 1) After calibrating the capacity of cell 120, the current of subsequent operation steps needs to be adjusted according to the actual capacity C0;

[0140] 2) Charge the battery 100 at a constant current of 1 / 3C to 3.8V, then charge it at 0.2C to 3.8V. Let it rest at room temperature for 30 minutes, record the initial voltage, weight, and ACIR, and take a picture.

[0141] 3) Attach the heating film to the battery 100 without any wrinkles, and place it at the rear of the large surface away from the explosion-proof valve 130 (if the width of the battery 100 is greater than the width of the heating film, place it in the center of that position). Each large surface should be covered with a piece of aerogel with a thickness of 1 mm.

[0142] 4) The heating film size requirement is 90 mm × 90 mm. If the large surface area of ​​the battery is smaller than the heating film size, a heating film must be customized according to the large surface area of ​​the battery for testing.

[0143] 5) Provided the heating film size meets the requirements, the rated power is 800 W, the internal resistance is 45 Ω~65 Ω, the rated voltage is 220 V, and the protection current is 4.5 A;

[0144] 6) Arrange the heating film and temperature points separately;

[0145] 7) Install the battery 100 clamp. Tighten the bolts on the clamp and control the bolt torque ≥ 5 N·m. The test clamp should be specially made according to the size of the battery cell 120. The length of the limit block is the same as the length of the clamp. The width of the limit block is the sum of the thickness of the battery 100 and the thickness of the aerogel. If the length of the battery 100 is greater than 600 mm, there should be no less than 8 screws on one side. If the length of the battery 100 is less than 600 mm, the screw spacing should be kept at 10 cm or less.

[0146] 8) Use a heating film to trigger thermal runaway of battery 100, record voltage and temperature data, and control the temperature of TC1 to 350 ℃~400 ℃ during the test until thermal runaway of cell 120 occurs; otherwise, the test is considered a failure.

[0147] 9) Observe for 1 hour after the test;

[0148] 10) Before and after the test, the battery 100 should be photographed and recorded, and the internal resistance and weight data should be recorded.

[0149] 5. Judgment criteria:

[0150]

[0151] The test results of the above embodiments and comparative examples are recorded in Table 1:

[0152] Table 1:

[0153]

[0154] Therefore, the parameters of battery 100 satisfy the following: This ensures that the battery 100 can vent smoothly in the event of thermal runaway of the cell 120, and also ensures the safety of the battery 100.

[0155] It should be noted that the embodiments referred to in the specification, such as "one embodiment," "embodiment," "exemplary embodiment," and "some embodiments," may include specific features, structures, or characteristics, but not all embodiments necessarily include that specific feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, when describing a specific feature, structure, or characteristic in conjunction with embodiments, implementing such a feature, structure, or characteristic in conjunction with other embodiments, whether explicitly described or not, is within the knowledge scope of those skilled in the art.

[0156] Generally speaking, terms should be understood at least in part by their use in context. For example, at least in part by context, the term "one or more" as used in the text can be used to describe any feature, structure, or characteristic of the singular meaning, or a combination of features, structures, or characteristics of the plural meaning. Similarly, at least in part by context, terms such as "one" can be understood to convey either singular or plural usage.

[0157] It should be readily understood that the terms “on,” “above,” and “on top of” in this application should be interpreted in the broadest possible sense, such that “on” means not only “directly on something” but also “on something” with an intermediate feature or layer therebetween, and that “above” or “on top of” means not only “on something” but also “on something” without an intermediate feature or layer therebetween (i.e., directly on something).

[0158] Furthermore, for ease of explanation, spatially relative terms such as "below," "below," "under," "above," and "above" may be used to describe the relationship of one element or feature relative to other elements or features as shown in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation other than those shown in the figures. The device may have other orientations (rotated 90° or in other orientations), and the spatially relative descriptive terms used herein may be interpreted accordingly.

[0159] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A battery, characterized in that, include: A housing (110) is provided with a pressure relief section (111), which opens under preset conditions; the area of ​​the pressure relief section (111) is S, and the unit of S is mm. 2 ; A battery cell (120) is disposed within the housing (110); The capacity of the battery (100) is A, and the unit of A is Ah; The shell (110) is filled with an electrolyte comprising lithium hexafluorophosphate and lithium difluorosulfonyl imide. The concentration of lithium hexafluorophosphate is μ, where μ is in mol / L; the concentration of lithium difluorosulfonyl imide is λ, where λ is in mol / L. Wherein, S, A, μ, and λ satisfy: .

2. The battery according to claim 1, characterized in that, The S, A, μ, and λ satisfy: .

3. The battery according to claim 1, characterized in that, The condition A satisfies: 50≤A≤500.

4. The battery according to claim 3, characterized in that, The condition A satisfies: 50≤A≤250.

5. The battery according to claim 1, characterized in that, The μ satisfies: 0.5 ≤ μ ≤ 1.

2.

6. The battery according to claim 5, characterized in that, The μ satisfies: 0.6 ≤ μ ≤ 1.

0.

7. The battery according to claim 1, characterized in that, The λ satisfies: 0 ≤ λ ≤ 0.

6.

8. The battery according to claim 7, characterized in that, The λ satisfies: 0.1≤λ≤0.

4.

9. The battery according to any one of claims 1-8, characterized in that, The number of pressure relief sections (111) is n, where n satisfies: n≥1; and S satisfies: .

10. The battery according to any one of claims 1-8, characterized in that, The housing (110) includes grooves (1111) for forming the pressure relief section (111); And / or, the housing (110) includes a thinning region for forming the pressure relief portion (111).

11. The battery according to claim 10, characterized in that, The notch (1111) is an open annular structure or a closed annular structure, and S is the area enclosed by the open annular structure or the closed annular structure.

12. The battery according to claim 10, characterized in that, The number of the grooves (1111) is multiple, and the multiple grooves (1111) are arranged in a radial structure, and the multiple grooves (1111) intersect at the radial center of the radial structure, and S is the area enclosed by the line connecting the free ends of the multiple grooves (1111).

13. The battery according to claim 10, characterized in that, The housing (110) also includes an explosion-proof valve (130), which is provided with the groove (1111) and / or the thinning area.

14. A battery device, characterized in that, include: The battery (100) as described in any one of claims 1-13.

15. An electrical appliance, characterized in that, include: The battery (100) as described in any one of claims 1-13; Or, the battery device as described in claim 14.

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