Battery and use thereof

Abstract

A battery and the use thereof. The battery comprises a bare cell and a stainless steel housing wrapped around the bare cell, and the battery satisfies the following relational expression: (A), wherein the value range of the relational expression is 0.5-10, Q is the capacity of the battery, l is the length of the stainless steel housing, x is the total size along the length direction of the bare cell of a lower plastic and a support inside the battery, h is the thickness of the stainless steel housing, w is the width of the stainless steel housing, v1 is the volume of the bare cell, and v2 is the electrolyte volume of the battery after formation.

Description

Batteries and their applications

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on August 31, 2023, with application number 202311120382.7, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application belongs to the field of battery technology and relates to a battery and its application. Background Art

[0003] When a lithium-ion battery experiences thermal runaway, a large amount of high-temperature material (temperatures can reach up to 800-900°C) is instantly generated, and high pressure is generated inside the battery. The melting point of the battery's aluminum shell is often 620-680°C. Therefore, the higher temperature inside the battery during thermal runaway will cause the aluminum shell to melt, resulting in non-directional eruption. To solve this problem, an explosion-proof valve is installed on the surface of the battery. The internal high pressure caused by thermal runaway breaks through the explosion-proof valve and ejects the high-temperature material in a directed manner. However, for short or thin batteries, the explosion-proof valve is generally located on the short side of the battery. The high-temperature material will not have time to migrate to the explosion-proof valve position along the length of the battery, and will melt the aluminum shell and eject from random positions on the surface.

[0004] Related technologies employ an explosion-proof valve positioned midway along the battery's long sides to shorten the diffusion path of high-temperature materials and achieve directional thermal runaway eruption. However, this design reduces internal battery space utilization, leading to a decrease in the battery's overall energy density.

[0005] Summary of the Invention

[0006] The present application provides a battery and its application, for example, a ternary system short battery and its application. The battery can solve the problem of non-directional blasting and eruption of aluminum shell short lithium-ion batteries in an out-of-control state. It not only has high space utilization and volume energy density, but also has high safety.

[0007] In a first aspect, the present application provides a battery comprising a bare cell and a stainless steel shell encapsulating the bare cell;

[0008] The battery satisfies the following relationship:

[0009] Among them, the value range of the relationship is 0.5-10, Q is the capacity of the battery, l is the length of the stainless steel shell, x is the total size of the lower plastic and bracket inside the battery along the length direction of the bare cell, h is the thickness of the stainless steel shell, w is the width of the stainless steel shell, V1 is the volume of the bare cell, and V2 is the volume of the electrolyte after the battery is formed.

[0010] In a second aspect, the present application provides an electronic device comprising the above-mentioned battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIG1 is a schematic diagram of the external structure of the battery described in Example 1 of the present application;

[0012] FIG2 is a schematic diagram of the internal structure of the battery described in Example 1 of the present application;

[0013] Among them, 1-stainless steel shell, 2-bare battery cell, 3-lower plastic and bracket, 4-top cover. DETAILED DESCRIPTION

[0014] The technical solution of this application is described below through specific implementation methods.

[0015] Lithium-ion secondary batteries are widely used in new energy vehicles due to their high operating voltage and energy density, long cycle life, lack of memory effect, and pollution-free properties. With the increasing popularity of electric vehicles, consumer demand for longer driving ranges is increasing, leading to a surge in interest in developing batteries with high capacity and high system integration. Short or thin batteries are characterized by being longer along one dimension in three-dimensional space and shorter or thinner along the other two. This allows for greater space utilization and a more compact design, significantly improving the energy density and system integration of bare cells and significantly increasing the range of electric vehicles.

[0016] To fully utilize the internal space of the battery casing, the tabs and top cover extend from both ends of the battery's length. This inevitably lengthens the path for high-temperature substances generated within the bare cell during thermal runaway to migrate to the explosion-proof valve and be ejected. In the event of thermal runaway, the internal temperature can reach as high as 800-900°C, far exceeding the melting point of the aluminum casing. Without sufficient time for the high-temperature substances to migrate to the explosion-proof valve and erupt, they melt the casing, ultimately causing a non-directional explosive eruption due to thermal runaway.

[0017] Since batteries are generally equipped with a lithium iron phosphate chemical system with good thermal stability and heat dissipation performance, the temperature of the high-temperature material inside the battery is lower during thermal runaway, and it has more time to migrate to the explosion-proof valve and be ejected; however, the battery of the present application can adopt a ternary system with poor thermal stability and heat dissipation performance far worse than the lithium iron phosphate system. Although the internal reaction of the ternary system is more violent during thermal runaway, resulting in uncontrolled eruption without directionality, the battery of the present application can still solve the non-directional explosion problem of the ternary system battery. The positive electrode active material of the battery includes at least one ternary positive electrode active material, and the ternary positive electrode active material includes at least one of nickel cobalt aluminum oxide and nickel cobalt manganese oxide.

[0018] The battery structure of this application includes a lower plastic and bracket, and a bare cell placed within a housing. The lower plastic and bracket are mounted on one end of the bare cell along its length, and on the other end on a top cover. The top cover is mounted at the openings at both ends of the housing. Explosion-proof valves are installed on both sides of the top cover without affecting the overall energy density of the battery.

[0019] The battery satisfies the following relationship:

[0020] In this application, the unit of Q is Ah, the unit of l is mm, the unit of x is mm, the unit of h is mm, the unit of w is mm, and the unit of V1 is cm 3 , the unit of V2 is cm 3 .

[0021] The value range of the relationship is 0.5-10, for example, it can be 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10, but is not limited to the listed values. Other unlisted values ​​within the numerical range are also applicable, which can be 0.5-6.

[0022] The total size of the lower plastic and bracket inside the battery of the present application along the length direction of the bare cell is within the above range and can satisfy the relationship. When the value of x is too small, it is easy to cause a short circuit in the cell. When the value of x is too large, the energy density of the cell will be reduced. The x is the sum of x1 and x2, x1>0, x2>0; x1 and x2 are the total lengths of the lower plastic and bracket on the left and right sides of the bare cell, respectively. The value range of x is 4-40mm, for example, it can be 5mm, 10mm, 20mm, 30mm or 40mm, but is not limited to the listed values. Other values ​​not listed in the numerical range are also applicable, and can be 10-30mm.

[0023] Optionally, the wall thickness of the stainless steel shell ranges from 0.05 to 1.0 mm, for example, it can be 0.05 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm or 0.8 mm, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable, and can also be 0.1 to 0.3 mm.

[0024] Optionally, the length l of the stainless steel shell ranges from 260 to 1200 mm, for example, it can be 260 mm, 300 mm, 500 mm, 700 mm, 900 mm, 1100 mm or 1200 mm, but is not limited to the listed values. Other unlisted values ​​within the numerical range are also applicable, and can be 280 to 650 mm.

[0025] Optionally, the thickness h of the stainless steel shell ranges from 8 to 30 mm, for example, 8 mm, 10 mm, 20 mm or 30 mm, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable, such as 12 to 25 mm.

[0026] Optionally, the width w of the stainless steel shell ranges from 80 to 180 mm, for example, it can be 80 mm, 100 mm, 120 mm, 140 mm, 160 mm or 180 mm, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable, and can be 90 to 125 mm.

[0027] The battery of the present application adopts a stainless steel shell, which can effectively suppress the problem of non-directional blasting and eruption of the battery in an out-of-control state. The present application provides a method of associating battery capacity with the selection of stainless steel shell. When the battery meets the above formula, a stainless steel shell is required to avoid non-directional blasting. The stainless steel shell can enhance safety and reliability and improve volume energy density while ensuring that the battery does not introduce other adverse effects.

[0028] Example 1

[0029] This embodiment provides a battery that can solve the problem of non-directional explosive eruption of aluminum-cased short lithium-ion batteries in an uncontrolled state. It not only has high space utilization and volume energy density, but also has high safety. The battery includes a bare cell 2 and a stainless steel casing 1 with a wall thickness of 0.2 mm. The stainless steel casing 1 is an alloy steel containing chromium and nickel.

[0030] The external structure of the battery is shown in FIG1 , and the internal structure is shown in FIG2 , wherein the lower plastic and bracket 3 and the bare cell 2 are placed inside the stainless steel shell 1 , with one side of the lower plastic and bracket 3 assembled to the end of the bare cell 2 along the length direction and the other side assembled to the top cover 4 , which is assembled to the openings at both ends of the stainless steel shell 1 ; explosion-proof valves are provided on the top covers 4 on both sides of the battery; the positive active material of the battery is nickel-cobalt-manganese oxide;

[0031] The battery satisfies the following relationship:

[0032] Wherein, Q represents the capacity of the battery, which is 145Ah; l represents the length of the stainless steel shell 1, which is 591.7mm; x represents the total size of the lower plastic and bracket 3 inside the battery along the length direction of the bare cell 2 (x=x1+x2), which is 20mm; h represents the thickness of the stainless steel shell 1, which is 14.9mm; w represents the width of the stainless steel shell 1, which is 111.4mm; V1 represents the volume of the bare cell 2, which is 769.96cm3 ; V2 represents the volume of the electrolyte after the battery is formed, and its value is 12.5cm 3 .

[0033] Example 2

[0034] This embodiment provides a battery, comprising a bare cell and a stainless steel shell with a wall thickness of 0.2 mm, wherein the stainless steel shell is an alloy steel containing chromium and nickel;

[0035] The structure of the battery is the same as that of Example 1, with explosion-proof valves provided on both side covers; the positive electrode active material of the battery is nickel-cobalt-manganese oxide;

[0036] The battery satisfies the following relationship:

[0037] Wherein, Q represents the capacity of the battery, which is 158Ah; l represents the length of the stainless steel shell, which is 591.7mm; x represents the total size of the lower plastic and bracket inside the battery along the length of the bare cell, which is 20mm; h represents the thickness of the stainless steel shell, which is 14.9mm; w represents the width of the stainless steel shell, which is 111.4mm; V1 represents the volume of the bare cell, which is 838.17cm 3 ; V2 represents the volume of the electrolyte after the battery is formed, and its value is 12.5cm 3 .

[0038] Example 3

[0039] This embodiment provides a battery, comprising a bare cell and a stainless steel shell with a wall thickness of 0.2 mm, wherein the stainless steel shell is an alloy steel containing chromium and nickel;

[0040] The structure of the battery is the same as that of Example 1, with explosion-proof valves provided on both side covers; the positive electrode active material of the battery is nickel-cobalt-manganese oxide;

[0041] The battery satisfies the following relationship:

[0042] Wherein, Q represents the capacity of the battery, which is 152Ah; l represents the length of the stainless steel shell, which is 591.7mm; x represents the total size of the lower plastic and bracket inside the battery along the length of the bare cell, which is 20mm; h represents the thickness of the stainless steel shell, which is 14.9mm; w represents the width of the stainless steel shell, which is 111.4mm; V1 represents the volume of the bare cell, which is 808.16cm 3 ; V2 represents the volume of the electrolyte after the battery is formed, and its value is 12.5cm 3 .

[0043] Example 4

[0044] This embodiment provides a battery, comprising a bare cell and a stainless steel shell with a wall thickness of 0.2 mm, wherein the stainless steel shell is an alloy steel containing chromium and nickel;

[0045] The structure of the battery is the same as that of Example 1, with explosion-proof valves provided on both side covers; the positive electrode active material of the battery is nickel-cobalt-manganese oxide;

[0046] The battery satisfies the following relationship:

[0047] Where Q represents the capacity of the battery, which is 72Ah; l represents the length of the stainless steel shell, which is 291.6mm; x represents the total size of the lower plastic and bracket inside the battery along the length of the bare cell, which is 20mm; h represents the thickness of the stainless steel shell, which is 14.9mm; w represents the width of the stainless steel shell, which is 111.4mm; V1 represents the volume of the bare cell, which is 401.17cm 3 ; V2 represents the volume of the electrolyte after the battery is formed, and its value is 20cm 3 .

[0048] Example 5

[0049] This embodiment provides a battery, comprising a bare cell and a stainless steel shell with a wall thickness of 0.2 mm, wherein the stainless steel shell is an alloy steel containing chromium and nickel;

[0050] The structure of the battery is the same as that of Example 1, with explosion-proof valves provided on both side covers; the positive electrode active material of the battery is nickel-cobalt-manganese oxide;

[0051] The battery satisfies the following relationship:

[0052] Where Q represents the capacity of the battery, which is 75Ah; l represents the length of the stainless steel shell, which is 291.6mm; x represents the total size of the lower plastic and bracket inside the battery along the length of the bare cell, which is 15mm; h represents the thickness of the stainless steel shell, which is 14.9mm; w represents the width of the stainless steel shell, which is 111.4mm; V1 represents the volume of the bare cell, which is 425.52cm 3 ; V2 represents the volume of the electrolyte after the battery is formed, and its value is 20cm 3 .

[0053] Example 6

[0054] This embodiment provides a battery, comprising a bare cell and a stainless steel shell with a wall thickness of 0.15 mm, wherein the stainless steel shell is an alloy steel containing chromium and nickel;

[0055] The structure of the battery is the same as that of Example 1, with explosion-proof valves provided on both side covers; the positive electrode active material of the battery is nickel-cobalt-manganese oxide;

[0056] The battery satisfies the following relationship:

[0057] Where Q represents the capacity of the battery, which is 154Ah; l represents the length of the stainless steel shell, which is 591.7mm; x represents the total size of the lower plastic and bracket inside the battery along the length of the bare cell, which is 15mm; h represents the thickness of the stainless steel shell, which is 14.9mm; w represents the width of the stainless steel shell, which is 111.4mm; V1 represents the volume of the bare cell, which is 818.28cm 3 ; V2 represents the volume of the electrolyte after the battery is formed, and its value is 13.5cm 3 .

[0058] Example 7

[0059] This embodiment provides a battery, comprising a bare cell and a stainless steel shell with a wall thickness of 0.1 mm, wherein the stainless steel shell is an alloy steel containing chromium and nickel;

[0060] The structure of the battery is the same as that of Example 1, with explosion-proof valves provided on both side covers; the positive electrode active material of the battery is nickel-cobalt-manganese oxide;

[0061] The battery satisfies the following relationship:

[0062] Wherein, Q represents the capacity of the battery, which is 155Ah; l represents the length of the stainless steel shell, which is 591.7mm; x represents the total size of the lower plastic and bracket inside the battery along the length of the bare cell, which is 20mm; h represents the thickness of the stainless steel shell, which is 14.9mm; w represents the width of the stainless steel shell, which is 111.4mm; V1 represents the volume of the bare cell, which is 821.12cm 3 ; V2 represents the volume of the electrolyte after the battery is formed, and its value is 10.5cm 3 .

[0063] Example 8

[0064] This embodiment provides a battery, which is the same as that of embodiment 1 except that the wall thickness of the stainless steel shell is 0.05 mm.

[0065] Example 9

[0066] This embodiment provides a battery, which is the same as that of embodiment 1 except that the wall thickness of the stainless steel shell is 0.8 mm.

[0067] Example 10

[0068] This embodiment provides a battery, which is the same as that of embodiment 1 except that the wall thickness of the stainless steel shell is 0.03 mm.

[0069] Example 11

[0070] This embodiment provides a battery, which is the same as that of embodiment 1 except that the wall thickness of the stainless steel shell is 1.0 mm.

[0071] Comparative Example 1

[0072] This comparative example provides a battery comprising a bare cell and an aluminum shell with a wall thickness of 0.4 mm;

[0073] The structure of the battery is the same as that of Example 1, with explosion-proof valves provided on both side covers; the positive electrode active material of the battery is nickel-cobalt-manganese oxide;

[0074] The battery satisfies the following relationship:

[0075] Wherein, Q represents the capacity of the battery, which is 147Ah; l represents the length of the stainless steel shell, which is 591.7mm; x represents the total size of the lower plastic and bracket inside the battery along the length of the bare cell, which is 20mm; h represents the thickness of the stainless steel shell, which is 14.9mm; w represents the width of the stainless steel shell, which is 111.4mm; V1 represents the volume of the bare cell, which is 772.58cm 3 ; V2 represents the volume of the electrolyte after the battery is formed, and its value is 12.5cm 3 .

[0076] Comparative Example 2

[0077] This comparative example provides a battery comprising a bare cell and an aluminum shell with a wall thickness of 0.35 mm;

[0078] The structure of the battery is the same as that of Example 1, with explosion-proof valves provided on both side covers; the positive electrode active material of the battery is nickel-cobalt-manganese oxide;

[0079] The battery satisfies the following relationship:

[0080] Wherein, Q represents the capacity of the battery, which is 75Ah; l represents the length of the stainless steel shell, which is 291.6mm; x represents the total size of the lower plastic and bracket inside the battery along the length of the bare cell, which is 15mm; h represents the thickness of the stainless steel shell, which is 14.9mm; w represents the width of the stainless steel shell, which is 111.4mm; V1 represents the volume of the bare cell, which is 410.68cm 3 ; V2 represents the volume of the electrolyte after the battery is formed, and its value is 20cm 3 .

[0081] Comparative Example 3

[0082] This comparative example provides a battery comprising a bare cell and a stainless steel shell with a wall thickness of 0.2 mm, wherein the stainless steel shell is an alloy steel containing chromium and nickel;

[0083] The structure of the battery is the same as that of Example 1, with explosion-proof valves provided on both side covers; the positive electrode active material of the battery is nickel-cobalt-manganese oxide;

[0084] The battery satisfies the following relationship:

[0085] Where Q represents the capacity of the battery, which is 75Ah; l represents the length of the stainless steel shell, which is 291.6mm; x represents the total size of the lower plastic and bracket inside the battery along the length of the bare cell, which is 15mm; h represents the thickness of the stainless steel shell, which is 14.9mm; w represents the width of the stainless steel shell, which is 111.4mm; V1 represents the volume of the bare cell, which is 435.68cm 3 ; V2 represents the volume of the electrolyte after the battery is formed, and its value is 20cm 3 .

[0086] The batteries of the above embodiments and comparative examples were subjected to a heating abuse test to monitor the explosion-proof valves and large-area explosion of the battery cells when the battery cells lose control. The test results are shown in Table 1.

[0087] Table 1

[0088] It can be seen from Table 1 that:

[0089] When the relationship in this application takes a value within the range of 0.5-10, a stainless steel shell can be used to solve the problem of non-directional explosive eruption after thermal runaway. Generally speaking, when the relationship takes a value less than 0.5, an aluminum shell can be used to prevent explosion. From a cost perspective, a stainless steel shell may not be used. When the relationship takes a value greater than 10, even a stainless steel shell cannot effectively suppress the non-directional explosion of the battery.

[0090] The wall thickness of the stainless steel shell of the present application will affect the safety and energy density of the battery. If the wall thickness of the stainless steel shell is too small, the safety performance of the battery will be reduced and non-directional explosion cannot be effectively suppressed. If the wall thickness of the stainless steel shell is too large, the mass capacity density of the battery will be reduced.

[0091] The battery provided in the present application can suppress the non-directional explosive eruption caused by thermal runaway of the battery. It can be seen from Example 1 and Comparative Examples 1 and 2 that the battery satisfies the relationship formula of the present application. Selecting a stainless steel shell can avoid large-area explosions, while an aluminum shell cannot avoid them. It can be seen from Example 1 and Comparative Example 3 that when the value of the relationship formula is greater than 10, even if a stainless steel shell is used, large-area explosions cannot be effectively suppressed. It can be seen from Example 1 and Examples 8, 9, 10 and 11 that the wall thickness of the stainless steel shell will also affect the safety and mass energy density of the battery of the present application.

[0092] In summary, the present application provides a battery and its application. Based on the correlation between battery capacity and stainless steel shell selection, when the battery satisfies the above formula, the use of a stainless steel shell can avoid non-directional blasting. The stainless steel shell can enhance safety and reliability while ensuring that the battery does not introduce other adverse effects. The battery can solve the problem of non-directional blasting and eruption of aluminum shell short lithium-ion batteries in an out-of-control state. It not only has high space utilization and volume energy density, but also has high safety.

Claims

1. A battery, comprising a bare cell and a stainless steel shell encapsulating the bare cell; The battery satisfies the following relationship: in, The relationship has a value range of 0.5-10, Q is the capacity of the battery, l is the length of the stainless steel shell, x is the total size of the lower plastic and bracket inside the battery along the length direction of the bare cell, h is the thickness of the stainless steel shell, w is the width of the stainless steel shell, V1 is the volume of the bare cell, and V2 is the volume of the electrolyte after the battery is formed.

2. The battery according to claim 1, wherein The value range of the relationship is 0.5-6.

3. The battery according to claim 1 or 2, further comprising top covers arranged on both sides of the bare battery cell, wherein the top covers are provided with explosion-proof valves; The stainless steel shell includes alloy steel containing at least one element of chromium, nickel or manganese.

4. The battery according to any one of claims 1 to 3, wherein: The positive electrode active material of the battery includes at least one ternary positive electrode active material; The ternary positive electrode active material includes at least one of nickel cobalt aluminum oxide and nickel cobalt manganese oxide.

5. The battery according to any one of claims 1 to 4, wherein: The wall thickness of the stainless steel shell ranges from 0.05 to 1.0 mm.

6. The battery according to claim 5, wherein The wall thickness of the stainless steel shell ranges from 0.1 to 0.3 mm.

7. The battery according to any one of claims 1 to 6, wherein: The length of the stainless steel shell ranges from 260 to 1200 mm.

8. The battery according to claim 7, wherein The length of the stainless steel shell ranges from 280 to 650 mm.

9. The battery according to any one of claims 1 to 8, wherein: The thickness of the stainless steel shell ranges from 8 to 30 mm.

10. The battery according to claim 9, wherein The thickness of the stainless steel shell ranges from 12 to 25 mm.

11. The battery according to any one of claims 1 to 10, wherein: The width of the stainless steel shell ranges from 80 to 180 mm.

12. The battery according to claim 11, wherein The width of the stainless steel shell ranges from 90 to 125 mm.

13. The battery according to any one of claims 1 to 12, wherein: The value range of x is 4-40 mm.

14. The battery according to claim 13, wherein The value range of x is 10-30 mm.

15. An electronic device comprising the battery according to any one of claims 1 to 14.

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