Battery and battery pack

Abstract

The present application relates to the technical field of batteries. Disclosed are a battery and a battery pack. The battery comprises a housing, a pressure relief mechanism and an electrode assembly, wherein the pressure relief mechanism is disposed on the housing, the theoretical design value of the area of an opening region of the pressure relief mechanism is S1, and the actual value of the area of the opening region of the pressure relief mechanism is Svalve; and / or, the electrode assembly is disposed in the housing, and the electrode assembly and the inner wall of the housing are spaced apart from each other to form a pressure relief channel, the theoretical design value of the equivalent sectional area of the pressure relief channel being S2, and the actual value of the equivalent sectional area of the pressure relief channel being Ssection; when the Svalve is determined, the number of pressure relief mechanisms is n1, and then n1=[S1 / Svalve]; and / or, when Ssection is determined, the number of pressure relief mechanisms is n2, and then n2=[S2 / Ssection]. The present application rationalizes the arrangement of pressure relief mechanisms on a housing, which ensures that a hot gas can be smoothly discharged from the pressure relief mechanisms when a battery undergoes thermal runaway, thereby suppressing the burst of the housing, and thus improving the safety performance of the battery.

Description

Batteries and battery packs

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the China Patent Office on December 7, 2023, with application number 202311670354.2 and invention name “Battery and Battery Pack”, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of battery technology, and in particular to batteries and battery packs. Background Art

[0004] As a high-energy structure, batteries inevitably face the problem of thermal runaway. The battery thermal runaway process is the process of energy and material release, where the material release mainly includes the release of gas.

[0005] Prior art uses a pressure relief mechanism installed in the battery housing to dissipate hot gases generated during thermal runaway. The hot gases flow through the pressure relief channel between the electrode assembly and the inner wall of the housing to the pressure relief mechanism. The number of pressure relief mechanisms can affect the safety of the battery housing. Irregularly configured pressure relief mechanisms can prevent hot gases from being effectively discharged through the pressure relief mechanisms, potentially leading to safety issues such as housing rupture and explosion caused by violent gas production during thermal runaway.

[0006] Summary of the Invention

[0007] In view of this, the present application provides a battery and a battery pack to solve the problem that the number of pressure relief mechanisms on existing batteries is not set in a standardized manner, resulting in the inability to effectively discharge hot air through the pressure relief mechanisms, which easily leads to shell rupture.

[0008] In a first aspect, the present application provides a battery, comprising:

[0009] case;

[0010] The pressure relief mechanism is provided on the housing. The theoretical design value of the opening area of ​​the pressure relief mechanism is S1, and the actual value of the opening area of ​​the pressure relief mechanism is S 阀 ;

[0011] And / or, the electrode group is arranged in the shell, and the electrode group is spaced apart from the inner wall of the shell to form a pressure relief channel, the theoretical design value of the equivalent cross-sectional area of ​​the pressure relief channel is S2, and the actual value of the equivalent cross-sectional area of ​​the pressure relief channel is S 截 ;

[0012] In S 阀 Under certain conditions, the number of pressure relief mechanisms is n1, then It is a rounding operation;

[0013] and / or, in S 截 Under certain conditions, the number of pressure relief mechanisms is n2, then

[0014] Beneficial effects: 阀 When it is determined, for example, when the pressure relief mechanism is a standard part or when the customer requires a specific pressure relief mechanism, S 阀 is a fixed value, which can be It is calculated that n1 pressure relief mechanisms need to be installed on the shell. 截 When determining, for example, when the shell dimensions or pole group dimensions cannot be changed due to some projects, or when the customer has customized requirements for the volume, energy, and density of the battery, S 截 is a fixed value, which can be Calculations show that n2 pressure relief mechanisms are required on the housing. The battery relates the number of pressure relief mechanisms to the area of ​​their openings and the equivalent cross-sectional area of ​​the pressure relief channel. The above formula is used to calculate the number of pressure relief mechanisms required on the housing under different conditions. This avoids the impact of too few pressure relief mechanisms on exhaust, or the cost increase of too many pressure relief mechanisms. This standardized number of pressure relief mechanisms allows for a rational placement of pressure relief mechanisms on the housing, ensuring that hot gas can be smoothly discharged from the pressure relief mechanisms in the event of thermal runaway, preventing housing rupture and improving battery safety.

[0015] In an optional embodiment, in S 阀 With S 截 When all are determined, the number of the pressure relief mechanisms is n3, then n3=n1*n2.

[0016] Beneficial Effects: The number of pressure relief mechanisms required on the housing is calculated as n3 by n3 = n1 * n2. This allows for the required number of pressure relief mechanisms on the housing to be standardized and rationalized under different conditions. The appropriate number of explosion-proof valves can be determined based on the battery's different material systems, capacity, rated voltage, and gas production characteristics such as gas production volume and rate, combined with design values ​​such as the area of ​​the pressure relief mechanism and the equivalent cross-sectional area of ​​the pressure relief channel.

[0017] In an optional implementation, the battery capacity is C, the battery rated voltage is V, the area coefficient of the pressure relief mechanism is α, 0.3≤α≤1, and S1=CVα.

[0018] Beneficial effect: The theoretical design value S1 of the opening area of ​​the pressure relief mechanism can be calculated according to S1=CVα.

[0019] In an optional embodiment, the equivalent area coefficient of the pressure relief channel is γ, 0.1≤γ≤0.5, S2=S1*γ.

[0020] Beneficial effect: The theoretical design value S2 of the equivalent cross-sectional area of ​​the pressure relief channel is calculated by S2=S1*γ.

[0021] In an optional embodiment, the length of the inner cavity of the shell is L, the height is H, and the thickness is T;

[0022] The gas space occupancy rate of the battery is β, 0.01≤β≤0.18, S 截 =LHTβ / (L+H) / 2.

[0023] Beneficial effects: Through S 截 =LHTβ / (L+H) / 2, calculate S 截 .

[0024] In an optional embodiment, the length of the pole group is l, the height is h, and β=1-hl / (HL).

[0025] Beneficial effect: When there is no input parameter of the gas space occupancy rate β, the β value can be determined according to the formula β=1-hl / (HL).

[0026] In an optional embodiment, a plurality of the pressure relief mechanisms are arranged at intervals on the side wall of the shell.

[0027] Beneficial effect: By arranging multiple pressure relief mechanisms at intervals on the side wall of the shell, when the pressure relief channel is partially blocked or the exhaust is not smooth, the gas can be discharged from other pressure relief mechanisms, ensuring that the hot gas can be smoothly discharged from the pressure relief mechanism when the battery thermal runaway occurs.

[0028] In an optional embodiment, a plurality of the pressure relief mechanisms are symmetrically arranged.

[0029] Beneficial effect: By arranging the pressure relief mechanism symmetrically, when the pressure relief channel on one side or a part of the pressure relief mechanism is blocked, the gas in the pressure relief channel can be discharged from the symmetrical pressure relief channel or pressure relief mechanism, ensuring smooth exhaust.

[0030] In an optional embodiment, the extension direction of the pole group is perpendicular to the plane where the pressure relief mechanism is located.

[0031] Beneficial effect: When the battery experiences thermal runaway, the hot gas can flow along the extension direction of the electrode group to the pressure relief mechanism to reduce the tortuosity of the pressure relief path, so as to quickly and effectively discharge the hot gas in the shell when the battery experiences thermal runaway, reducing the risk of battery explosion.

[0032] In a second aspect, the present application also provides a battery pack, including a battery.

[0033] Beneficial effect: The batteries in the battery pack associate the number of pressure relief mechanisms with the area of ​​the opening area of ​​the pressure relief mechanism and the equivalent cross-sectional area of ​​the pressure relief channel, and calculate the number of pressure relief mechanisms that need to be set on the shell under different conditions, so as to avoid the impact of too few pressure relief mechanisms on exhaust, or too many pressure relief mechanisms increasing costs. The number of pressure relief mechanisms is determined in a standardized manner, so that the pressure relief mechanisms are reasonably set on the shell, ensuring that hot gas can be smoothly discharged from the pressure relief mechanism when the battery thermal runaway occurs, suppressing the explosion of the shell, and improving the safety performance of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0035] FIG1 is a cross-sectional view from a first angle of a battery according to an embodiment of the present application;

[0036] FIG2 is a cross-sectional view from a second angle of a battery according to an embodiment of the present application;

[0037] FIG3 shows an installation method of a pressure relief mechanism in a battery according to an embodiment of the present application;

[0038] FIG4 shows another installation method of a pressure relief mechanism in a battery according to an embodiment of the present application;

[0039] FIG5 shows another installation method of a pressure relief mechanism in a battery according to an embodiment of the present application;

[0040] FIG6 shows another installation method of a pressure relief mechanism in a battery according to an embodiment of the present application;

[0041] FIG7 shows another installation method of a pressure relief mechanism in a battery according to an embodiment of the present application;

[0042] FIG8 shows another installation method of a pressure relief mechanism in a battery according to an embodiment of the present application;

[0043] FIG9 shows another installation method of a pressure relief mechanism in a battery according to an embodiment of the present application;

[0044] FIG10 is another installation method of a pressure relief mechanism in a battery according to an embodiment of the present application;

[0045] FIG11 is another installation method of a pressure relief mechanism in a battery according to an embodiment of the present application;

[0046] FIG12 shows another installation method of a pressure relief mechanism in a battery according to an embodiment of the present application;

[0047] FIG13 shows another installation method of a pressure relief mechanism in a battery according to an embodiment of the present application;

[0048] FIG14 shows another installation method of a pressure relief mechanism in a battery according to an embodiment of the present application.

[0049] Explanation of reference numerals: 1. Shell; 2. Pressure relief mechanism; 3. Pole group; 301 , pole ear; 4. Pressure relief channel. DETAILED DESCRIPTION

[0050] To make the purpose, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of this application.

[0051] In related technologies, a pressure relief mechanism is installed in the battery housing to discharge the hot gas generated during thermal runaway. The hot gas flows through the pressure relief channel between the electrode assembly and the inner wall of the housing to the pressure relief mechanism. The number of pressure relief mechanisms can affect the safety of the battery housing. Irregularly setting the number of pressure relief mechanisms can prevent the hot gas from being effectively discharged through the pressure relief mechanisms, leading to safety issues such as housing rupture and explosion caused by the violent gas production during thermal runaway.

[0052] The following describes an embodiment of the present application in conjunction with Figures 1 to 14.

[0053] According to an embodiment of the present application, on one hand, as shown in FIG. 1 and FIG. 2 , a battery is provided, including a housing 1 , a pressure relief mechanism 2 and an electrode group 3 .

[0054] Specifically, as shown in FIG1 , the pressure relief mechanism 2 is provided on the housing 1 , wherein the theoretical design value of the opening area of ​​the pressure relief mechanism 2 is S1 , and the actual value of the opening area of ​​the pressure relief mechanism 2 is S 阀 It can be understood that S1 is the minimum value of the opening area of ​​the pressure relief mechanism 2 on the housing 1, and the actual value S of the opening area of ​​the pressure relief mechanism 2 is 阀 It should be greater than or equal to the theoretical design value S1 of the opening area of ​​the pressure relief mechanism 2.

[0055] Specifically, as shown in FIG1 , the electrode group 3 is disposed inside the housing 1, and the electrode group 3 is spaced apart from the inner wall of the housing 1, so that a pressure relief channel 4 is formed between the electrode group 3 and the inner wall of the housing 1. The theoretical design value of the equivalent cross-sectional area of ​​the pressure relief channel 4 is S2, and the actual value of the equivalent cross-sectional area of ​​the pressure relief channel 4 is S 截 .

[0056] It should be noted that the equivalent cross-sectional area of ​​the pressure relief channel 4 is the average value of the cross-sectional areas of the pressure relief channels 4 at various locations.

[0057] In S 阀 Under certain conditions, the number of pressure relief mechanisms 2 is n1, then That is, in S 阀 When determined, and S 阀 <S1, passed It is calculated that n1 pressure relief mechanisms 2 need to be provided on the housing 1 .

[0058] and / or, in S 截 Under certain conditions, the number of pressure relief mechanisms 2 is n2, then That is, in S 截 When confirmed, It is calculated that n2 pressure relief mechanisms 2 need to be provided on the housing 1 .

[0059] It should be noted that For the rounding operation, the rounding operation is to round a value up to the nearest integer. The rule of the rounding operation is: if x is an integer, the result of the rounding is x itself; if x is a decimal, the result of the rounding is the smallest integer greater than x. For example, the rounding operation The result is 4, rounded up The result is 3.

[0060] This battery, in S 阀 When it is determined, for example, when the pressure relief mechanism 2 is a standard part or when the customer requires a specific pressure relief mechanism 2, S 阀 is a fixed value, which can be It is calculated that n1 pressure relief mechanisms 2 need to be installed on the housing 1. 截 When determining, for example, when the dimensions of the shell 1 or the dimensions of the electrode group 3 cannot be changed due to some projects, or when the customer has customized requirements for the volume, energy, and density of the battery, S 截 is a fixed value, which can be It is calculated that n2 pressure relief mechanisms 2 need to be installed on the housing 1. The battery associates the number of pressure relief mechanisms 2 with the area of ​​the opening area of ​​the pressure relief mechanism 2 and the equivalent cross-sectional area of ​​the pressure relief channel 4. The above formula is used to calculate the number of pressure relief mechanisms 2 required on the housing 1 under different conditions. This avoids the impact of too few pressure relief mechanisms 2 on exhaust or the increase in cost due to too many pressure relief mechanisms 2. The number of pressure relief mechanisms 2 is determined in a standardized manner, making the installation of pressure relief mechanisms 2 on the housing 1 reasonable. This ensures that hot gas can be smoothly discharged from the pressure relief mechanisms 2 in the event of thermal runaway of the battery, suppressing the explosion of the housing 1 and improving the safety performance of the battery.

[0061] Furthermore, the standardized setting of the pressure relief mechanism 2 can be directly verified on the square battery cell without the need for re-molding, thereby reducing costs and shortening the development cycle.

[0062] The pressure relief mechanism 2 may be an explosion-proof valve. A mounting hole is provided on one end face of the housing 1, and the explosion-proof valve is mounted in the mounting hole. The specific configuration is not limited herein and may be configured according to actual needs.

[0063] In one embodiment, in S 阀 With S 截 In the state where all are determined, the number of pressure relief mechanisms 2 is n3, then n3=n1*n2. 阀 With S 截 When all are determined, the number of pressure relief mechanisms 2 required on the housing 1 is calculated as n3 using n3 = n1 * n2. This allows for the required number of pressure relief mechanisms 2 on the housing 1 under different conditions, standardizing and rationalizing the placement of pressure relief mechanisms 2 on the housing 1. The appropriate number of explosion-proof valves can be determined based on the battery's material system, capacity, rated voltage, and gas production characteristics such as gas production volume and rate, combined with design values ​​such as the area of ​​the pressure relief mechanism 2 and the equivalent cross-sectional area of ​​the pressure relief channel 4.

[0064] In one embodiment, the battery capacity is C, the rated voltage of the battery is V, the area coefficient of the pressure relief mechanism 2 is α, 0.3≤α≤1, S1=CVα, and the theoretical design value S1 of the opening area of ​​the pressure relief mechanism 2 can be calculated according to S1=CVα, or a fixed value can be input in advance.

[0065] Among them, the area coefficient α is related to the material system. The more active the material system is, the higher the energy density is, and the larger the area coefficient α is.

[0066] First, α is obtained by fitting a small batch of experimental data, and then promoted and applied after verification.

[0067] The area coefficient α is directly related to the active properties of the material system. The greater the gas production of the material reaction and the faster the gas production rate, the larger the required area of ​​the corresponding pressure relief mechanism 2. The reference value of the pressure relief area of ​​the pressure relief mechanism 2 can be obtained through the battery thermal runaway gas production test experiment: the gas production per ampere-hour of different material systems ranges from 0.3L to 1.8L. Assuming that the pressure resistance of the shell 1 is the same and all gases are required to be released in the same time and exhaust rate, then the area of ​​the pressure relief mechanism 2 should be positively correlated with the gas production per ampere-hour of the material system. Under ideal conditions, it may be linearly correlated. This is the theoretical premise for the value of the area coefficient α.

[0068] Secondly, Tables 1 and 2 show the measured gas production per ampere-hour for different material systems. Based on this premise, calculations based on existing products indicate that a coefficient α exists, approximately equal to the ratio of the product of the battery capacity and voltage to the area of ​​the pressure relief mechanism 2. The area coefficient α has a relatively large range of values.

[0069] Then, after classifying the material systems, the reference value ranges of Tables 1 and 2 were obtained and corrected, which can be narrowed down to about 0.1 based on the measured gas production data.

[0070] Finally, by considering the impact of design factors such as injection coefficient and compaction density on gas production, designers can ultimately narrow the fluctuation of the value range to within 0.1.

[0071] For example: For a power iron-lithium system battery cell, the measured gas production is known to be 1.0L / Ah, and the area coefficient α ranges from 0.4 to 0.7. Based on the corresponding relationship between the intervals, the range can be narrowed to 0.6-0.7. Considering the design of the battery cell, its energy density is relatively high, and the value can be taken as 0.65-0.7.

[0072] Special note: For non-pure liquid electrolyte systems, such as solid and semi-solid (condensed state is a type of semi-solid), ternary lithium is selected as the positive electrode material; if it is a system mixed with multiple materials, the gas production is calculated according to the proportion weight of the mixing, or the gas production can be measured and then the area coefficient α is taken as a reference.

[0073] Table 1

[0074] Table 2

[0075] In one embodiment, the equivalent area coefficient of the pressure relief channel 4 is γ, 0.1≤γ≤0.5, S2=S1*γ, and the theoretical design value S2 of the equivalent cross-sectional area of ​​the pressure relief channel 4 is calculated by S2=S1*γ.

[0076] The equivalent area coefficient γ of pressure relief channel 4 is directly related to the gas production rate. γ was first determined by fitting small-batch experimental data and then, after verification, promoted for application. The theoretical basis for determining γ's value is: assuming the same gas production and explosion-proof valve area, the faster the internal gas production rate, the larger the required internal gas space. By collecting test data from different systems and fitting the relationship curve between S1 and S2, we can determine the equivalent cross-sectional area coefficient γ of pressure relief channel 4. See Tables 3 and 4.

[0077] Table 3

[0078] Table 4

[0079] In one embodiment, the length of the inner cavity of the shell 1 is L, the height is H, and the thickness is T; the gas space occupancy rate of the battery is β, 0.01≤β≤0.18, S 截 =LHTβ / (L+H) / 2. According to the L, H, T of the shell 1 and the gas space occupancy β of the battery, the S 截 =LHTβ / (L+H) / 2, calculate S 截 .

[0080] In one embodiment, the thickness of the electrode group 3 is approximately equal to the thickness of the inner cavity of the shell 1, the length of the electrode group 3 is l, the height is h, β = 1-hl / (HL), and when there is no input parameter of the gas space occupancy β, the β value can be determined according to the formula β = 1-hl / (HL).

[0081] In one embodiment, as shown in Figures 3 to 14, a plurality of the pressure relief mechanisms 2 are arranged at intervals on the side walls of the shell 1. By arranging a plurality of pressure relief mechanisms 2 at intervals on the side walls of the shell 1, when the pressure relief channel 4 is partially blocked or the exhaust is not smooth, the gas can be discharged from other pressure relief mechanisms 2, thereby ensuring that the hot gas can be smoothly discharged from the pressure relief mechanism 2 when the battery thermal runaway occurs.

[0082] For example, the pressure relief mechanism 2 can be arranged on the same side of the housing 1 , or on two opposite sides of the housing 1 .

[0083] In one embodiment, as shown in Figures 3, 4, 5, 7 and 8, multiple pressure relief mechanisms 2 are symmetrically arranged. By symmetrically arranging the pressure relief mechanisms 2, when the pressure relief channel 4 on one side or a part of the pressure relief mechanism 2 is blocked, the gas in the pressure relief channel 4 can be discharged from the symmetrical pressure relief channel 4 or pressure relief mechanism 2, ensuring smooth exhaust.

[0084] For example, the pressure relief mechanism 2 may be arranged in a centrally symmetrical manner or in a mirror-symmetrical manner.

[0085] In one embodiment, the extension direction of the electrode group 3 is perpendicular to the plane where the pressure relief mechanism 2 is located, and the extension direction includes the long side or the short side. When thermal runaway occurs in the battery, the hot gas can flow along the extension direction of the electrode group 3 to the pressure relief mechanism 2 to reduce the tortuosity of the pressure relief path, so as to quickly and effectively discharge the hot gas in the shell 1 when the battery thermal runaway occurs, thereby reducing the risk of battery explosion.

[0086] As shown in Figures 3 to 14, the housing 1 has openings at both ends, with a positive electrode cover plate and a negative electrode cover plate respectively disposed on the two openings. The positive electrode cover plate is provided with a positive electrode column, and the negative electrode cover plate is provided with a negative electrode column. The openings, the positive electrode cover plate, the negative electrode cover plate, the positive electrode column, and the negative electrode column are not shown in the figures. The electrode group 3 has tabs 301 at both ends, and the tabs 301 at both ends of the electrode group 3 are respectively a positive electrode tab 301 and a negative electrode tab 301. The positive electrode tab 301 is connected to the positive electrode connecting plate, and the negative electrode tab 301 is connected to the negative electrode connecting plate. The positive electrode tab is connected to the positive electrode column, and the negative electrode column is connected to the negative electrode column. The positive electrode column and the negative electrode column both extend into the housing 1 into the pressure relief channel 4. The positive electrode column and the positive electrode tab 301 are supported between the electrode group 3 and the positive electrode cover plate, and the negative electrode column and the negative electrode tab 301 are supported between the electrode group 3 and the negative electrode cover plate.

[0087] Example 1

[0088] In S 阀 In a certain state, S 阀 200mm 2 , the material system is medium nickel, C is 117Ah, V is 3.7V, α is 0.8, and from S1=CVα, we can calculate S1=117*3.7*0.8=346.32mm 2 ,pass Then calculate That is, the number of explosion-proof valves is 2. Then, a battery thermal runaway test is carried out to verify the cracking of shell 1. The calculation results and the cracking condition of shell 1 are shown in Tables 5 and 6.

[0089] Example 2

[0090] In S 阀 In a certain state, S 阀 300mm 2 , the material system is medium nickel, C is 117Ah, V is 3.7V, α is 0.8, and from S1=CVα, we can calculate S1=117*3.7*0.8=346.32mm 2 ,pass Then calculate That is, the number of explosion-proof valves is 2. Then, a battery thermal runaway test is carried out to verify the cracking of shell 1. The calculation results and the cracking condition of shell 1 are shown in Tables 5 and 6.

[0091] Comparative Example 1

[0092] In S 阀 In a certain state, S 阀 300mm 2 , the material system is medium nickel, C is 117Ah, V is 3.7V, α is 0.8, and from S1=CVα, we can calculate S1=117*3.7*0.8=346.32mm 2 ,pass Then calculate Theoretically, the number of explosion-proof valves should be set to 2. However, we set one explosion-proof valve on the shell 1 for comparison with Example 2 in which two explosion-proof valves were set. Then, a battery thermal runaway test was carried out to verify the cracking of the shell 1. The calculation results and the cracking condition of the shell 1 are shown in Tables 5 and 6.

[0093] Table 5

[0094] Table 6

[0095] Example 3

[0096] In S 阀 In a certain state, S 阀 300mm 2 , the material system is high nickel, C is 136Ah, V is 3.65V, α is 1, and from S1=CVα, we can calculate S1=136*3.65*1=496.4mm 2 ,pass Then calculate That is, the number of explosion-proof valves is 2. Then, a battery thermal runaway test is carried out to verify the cracking of shell 1. The calculation results and the cracking condition of shell 1 are shown in Tables 7 and 8.

[0097] Comparative Example 2

[0098] In S 阀 In a certain state, S 阀 300mm 2 , the material system is high nickel, C is 136Ah, V is 3.65V, α is 1, and from S1=CVα, we can calculate S1=136*3.65*1=496.4mm 2 ,pass Then calculate That is, the number of explosion-proof valves is 2. However, we set one explosion-proof valve on the shell 1 for comparison with Example 3 in which two explosion-proof valves are set. Then, a battery thermal runaway test was carried out to verify the cracking of the shell 1. The calculation results and the cracking condition of the shell 1 are shown in Tables 7 and 8.

[0099] Table 7

[0100] Table 8

[0101] Example 4

[0102] In S 截 In a certain state, S 截 119.1mm 2 , the material system is high nickel doped silicon, C is 165Ah, V is 3.72V, α is 0.9, γ is 0.45, from S2=S1*γ, S1=CVα, calculated S2=CVαγ=165*3.72*0.9*0.45=248.589, through Calculate That is, the number of explosion-proof valves is 3. Then, a battery thermal runaway test is carried out to verify the cracking of shell 1. The calculation results and the cracking condition of shell 1 are shown in Tables 9 and 10.

[0103] Example 5

[0104] In S 截 In a certain state, S 截 147.2mm 2 , the material system is high nickel doped silicon, C is 165Ah, V is 3.72V, α is 0.9, γ is 0.45, from S2=S1*γ, S1=CVα, calculated S2=CVαγ=165*3.72*0.9*0.45=248.589, through Calculate That is, the number of explosion-proof valves is 2. Then, a battery thermal runaway test is carried out to verify the cracking of shell 1. The calculation results and the cracking condition of shell 1 are shown in Tables 9 and 10.

[0105] Comparative Example 3

[0106] In S 阀 With S 截 When both are determined, S 阀 300mm 2 , S 截 132mm 2 , the material system is high nickel doped silicon, C is 165Ah, V is 3.72V, α is 0.9, γ is 0.45, from S2 = S1 * γ, S1 = CVα, calculated S1 = CVα = 165 * 3.72 * 0.9 = 552.42 and S2 = CVαγ = 165 * 3.72 * 0.9 * 0.45 = 248.589, through Then n3 = n1 * n2 = 2 * 2 = 4, that is, the number of explosion-proof valves is 4. However, we set 3 explosion-proof valves on the shell 1 for comparison with the actual 4 explosion-proof valves that should be set. Then, we carried out a battery thermal runaway test to verify the cracking of the shell 1. The calculation results and the cracking situation of the shell 1 are shown in Tables 9 and 10.

[0107] Table 9

[0108] Table 10

[0109] Example 6

[0110] In S 截 In a certain state, S 截 23.5mm 2 , the material system is iron lithium system, C is 106Ah, V is 3.19V, α is 0.65, γ is 0.2, from S2=S1*γ, S1=CVα, it is calculated that S2=CVαγ=106*3.19*0.65*0.2=43.9582, through Calculate That is, the number of explosion-proof valves is 2. Then, a battery thermal runaway test is carried out to verify the cracking of shell 1. The calculation results and the cracking condition of shell 1 are shown in Tables 11 and 12.

[0111] Example 7

[0112] In S 阀 With S 截 When both are determined, S 阀 250mm 2 , S 截 20.9mm 2 , the material system is iron lithium system, C is 106Ah, V is 3.19V, α is 0.65, γ is 0.2, from S2=S1*γ, S1=CVα, it is calculated that S1=CVα=106*3.19*0.65=219.791 and S2=CVαγ=106*3.19*0.65*0.2=43.9582, through Then n3=n1*n2=1*3=3, that is, the number of explosion-proof valves is 3. However, we set one explosion-proof valve on the shell 1 for comparison with the actual setting of 3 explosion-proof valves, and then carried out a battery thermal runaway test to verify the cracking of the shell 1. The calculation results and the cracking condition of the shell 1 are shown in Tables 11 and 12.

[0113] Example 8

[0114] In S 阀 With S 截 When both are determined, S 阀250mm 2 , S 截 24.9mm 2 , the material system is iron lithium system, C is 106Ah, V is 3.19V, α is 0.65, γ is 0.2, from S2=S1*γ, S1=CVα, it is calculated that S1=CVα=106*3.19*0.65=219.791 and S2=CVαγ=106*3.19*0.65*0.2=43.9582, through Then n3=n1*n2=1*2=2, that is, the number of explosion-proof valves is 2. Then, the battery thermal runaway test is carried out to verify the cracking of shell 1. The calculation results and the cracking condition of shell 1 are shown in Tables 11 and 12.

[0115] Example 9

[0116] In S 阀 With S 截 When both are determined, S 阀 250mm 2 , S 截 68.1mm 2 , the material system is iron lithium system, C is 198Ah, V is 3.2V, α is 0.7, γ is 0.2, from S2=S1*γ, S1=CVα, it is calculated that S1=CVα=198*3.2*0.7=443.52 and S2=CVαγ=198*3.2*0.7*0.2=88.704, through Then n3=n1*n2=2*2=4, that is, the number of explosion-proof valves is 4. Then the battery thermal runaway test is carried out to verify the cracking of shell 1. The calculation results and the cracking condition of shell 1 are shown in Tables 11 and 12.

[0117] Example 10

[0118] In S 阀 With S 截 When both are determined, S 阀 250mm 2 , S 截 41.9mm 2 , the material system is iron lithium system, C is 198Ah, V is 3.2V, α is 0.7, γ is 0.2, from S2=S1*γ, S1=CVα, it is calculated that S1=CVα=198*3.2*0.7=443.52 and S2=CVαγ=198*3.2*0.7*0.2=88.704, through Then n3=n1*n2=2*3=6, that is, the number of explosion-proof valves is 6. Then the battery thermal runaway test is carried out to verify the cracking of shell 1. The calculation results and the cracking condition of shell 1 are shown in Tables 11 and 12.

[0119] Example 11

[0120] In S 阀 With S 截 When both are determined, S 阀 250mm 2 , S 截 34.9mm 2 , the material system is iron lithium system, C is 198Ah, V is 3.2V, α is 0.7, γ is 0.2, from S2=S1*γ, S1=CVα, it is calculated that S1=CVα=198*3.2*0.7=443.52 and S2=CVαγ=198*3.2*0.7*0.2=88.704, through Then n3 = n1 * n2 = 2 * 3 = 6, that is, the number of explosion-proof valves is 6. However, we set 4 explosion-proof valves on the shell 1 for comparison with the actual 6 explosion-proof valves that should be set. Then, we carried out a battery thermal runaway test to verify the cracking of the shell 1. The calculation results and the cracking situation of the shell 1 are shown in Tables 11 and 12.

[0121] Table 11

[0122] Table 12

[0123] According to an embodiment of the present application, on the other hand, a battery pack is provided, comprising the above-mentioned battery.

[0124] In this battery pack, the batteries in the battery pack associate the number of pressure relief mechanisms 2 with the area of ​​the opening area of ​​the pressure relief mechanism 2 and the equivalent cross-sectional area of ​​the pressure relief channel 4, and calculate the number of pressure relief mechanisms 2 that need to be set on the shell 1 under different conditions to avoid the impact of too few pressure relief mechanisms 2 on exhaust or the increase in cost due to too many pressure relief mechanisms 2. The number of pressure relief mechanisms 2 is determined in a standardized manner, so that the setting of the pressure relief mechanisms 2 on the shell 1 is reasonable, ensuring that hot gas can be smoothly discharged from the pressure relief mechanism 2 when the battery thermal runaway occurs, suppressing the explosion of the shell 1, and improving the safety performance of the battery.

[0125] Although the embodiments of the present application have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present application, and such modifications and variations shall fall within the scope defined by the appended claims.

Claims

1. A battery, characterized in that: include: case; The pressure relief mechanism is provided on the housing. The theoretical design value of the opening area of ​​the pressure relief mechanism is S1, and the actual value of the opening area of ​​the pressure relief mechanism is S 阀 ; And / or, the electrode group is arranged in the shell, and the electrode group is spaced from the inner wall of the shell to form a pressure relief channel, the theoretical design value of the equivalent cross-sectional area of ​​the pressure relief channel is S2, and the actual value of the equivalent cross-sectional area of ​​the pressure relief channel is S 截 ; In S 阀 Under certain conditions, the number of pressure relief mechanisms is n1, then It is the rounding operation; and / or, in S 截 Under certain conditions, the number of pressure relief mechanisms is n2, then 2. The battery according to claim 1, characterized in that In S 阀 With S 截 When all are determined, the number of the pressure relief mechanisms is n3, then n3=n1*n2.

3. The battery according to claim 1 or 2, characterized in that: The battery capacity is C, the battery rated voltage is V, the area coefficient of the pressure relief mechanism is α, 0.3≤α≤1, S1=CVα.

4. The battery according to claim 3, characterized in that The equivalent area coefficient of the pressure relief channel is γ, 0.1≤γ≤0.5, S2=S1*γ.

5. The battery according to claim 1 or 2, characterized in that: The inner cavity of the shell has a length of L, a height of H, and a thickness of T; The gas space occupancy rate of the battery is β, 0.01≤β≤0.18, S 截 =LHTβ / (L+H) / 2.

6. The battery according to claim 5, characterized in that The length of the pole group is l, the height is h, and β=1-hl / (HL).

7. The battery according to claim 1 or 2, characterized in that: A plurality of the pressure relief mechanisms are arranged at intervals on the side wall of the shell.

8. The battery according to claim 7, characterized in that The plurality of pressure relief mechanisms are symmetrically arranged.

9. The battery according to claim 1 or 2, characterized in that: The extension direction of the pole group is perpendicular to the plane where the pressure relief mechanism is located.

10. A battery pack, characterized in that: A battery comprising the battery according to any one of claims 1 to 9.

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