CN115693011A - Shell member, battery monomer, battery and consumer - Google Patents

Shell member, battery monomer, battery and consumer Download PDF

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Publication number
CN115693011A
CN115693011A CN202211441874.1A CN202211441874A CN115693011A CN 115693011 A CN115693011 A CN 115693011A CN 202211441874 A CN202211441874 A CN 202211441874A CN 115693011 A CN115693011 A CN 115693011A
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China
Prior art keywords
groove
equal
area
housing
battery
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CN202211441874.1A
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CN115693011B (en
Inventor
陈小波
顾明光
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Contemporary Amperex Technology Co Ltd
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Contemporary Amperex Technology Co Ltd
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

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Abstract

The embodiment of the application provides a shell part, a battery monomer, a battery and electric equipment. The shell component comprises a non-weak area and a weak area which are integrally formed, the shell component is provided with a groove portion, the non-weak area is formed around the groove portion, the weak area is formed at the bottom of the groove portion, and the weak area is configured to be damaged when the battery cell releases internal pressure. Wherein the average grain size of the weak region is S 1 The average grain size of the non-weakened region is S 2 ，S 1 /S 2 Less than or equal to 0.9. Reduce the average grain size of the weak area and improve the mechanical property of the material in the weak areaThe toughness and the fatigue resistance of the weak area are improved, the risk that the weak area is damaged under the normal use condition of the single battery is reduced, and the service life of the single battery is prolonged.

Description

Shell member, battery monomer, battery and consumer
Technical Field
The application relates to the technical field of batteries, in particular to a shell component, a battery monomer, a battery and electric equipment.
Background
With the development of new energy technology, batteries are more and more widely used, for example, in mobile phones, notebook computers, battery cars, electric automobiles, electric airplanes, electric ships, electric toy cars, electric ships, electric toy airplanes, electric tools, and the like.
In addition to improving the safety of the battery cell, the service life of the battery cell is also a problem to be considered in the development of battery technology. Therefore, how to increase the service life of the battery cell is a problem to be solved urgently in the battery technology.
Disclosure of Invention
The embodiment of the application provides a shell part, a single battery, a battery and electric equipment, and can effectively prolong the service life of the battery.
In a first aspect, embodiments of the present application provide an enclosure component for a battery cell, including a non-weak area and a weak area that are integrally formed, the enclosure component being provided with a groove portion, the non-weak area being formed around the groove portion, the weak area being formed at a bottom of the groove portion, the weak area being configured to be damaged when the battery cell discharges internal pressure; wherein the average grain size of the weak region is S 1 The average grain size of the non-weakened region is S 2 And satisfies the following conditions: s. the 1 /S 2 ≤0.9。
In the above technical scheme, S 1 /S 2 The average grain size of the weak area is less than or equal to 0.9, the difference between the average grain size of the weak area and the average grain size of the non-weak area is large, the average grain size of the weak area is reduced, the mechanical property of materials of the weak area is improved, the toughness and the fatigue resistance of the weak area are improved, the risk that the weak area is damaged under the normal use condition of the battery monomer is reduced, and the service life of the battery monomer is prolonged.
In some embodiments, S 1 /S 2 ≥0.05。S 1 /S 2 And when the pressure of the battery monomer is too small, the forming difficulty of the weak area is increased, the strength of the weak area is too high, the difficulty that the weak area is damaged when the battery monomer is out of control due to heat is increased, and the situation that the pressure release is not timely is easy to occur. Thus, S 1 /S 2 The pressure relief method has the advantages that the pressure relief method is larger than or equal to 0.05, the forming difficulty of a forming weak area is reduced, and the pressure relief timeliness of the single battery in thermal runaway is improved.
In some embodiments, 0.1 ≦ S 1 /S 2 Less than or equal to 0.5. The comprehensive performance of the shell part is better, the weak area can be guaranteed to have enough strength under the condition that the weak area can be timely damaged when the battery monomer is out of control due to heat, and the battery monomer can be normally used.
In some embodiments, 0.4 μm ≦ S 1 ≤75μm。S 1 Too large, the toughness and fatigue resistance of the weak area are poor; s. the 1 When the pressure of the battery cell is too low, the forming difficulty of the weak area is high, the strength of the weak area is too high, the difficulty that the weak area is damaged when the battery cell is out of control due to heat is increased, and the situation that the pressure is not released timely is easy to occur. Therefore, 0.4 μm. Ltoreq.S 1 Less than or equal to 75 microns, on one hand, the forming difficulty of a weak area is reduced, and the pressure relief timeliness of the single battery when thermal runaway is improved; on the other hand, the toughness and the fatigue resistance of the weak area are improved, and the risk that the weak area is damaged under the normal use condition of the battery monomer is reduced.
In some embodiments, 1 μm ≦ S 1 Less than or equal to 10 mu m. The comprehensive performance of the shell part is better, the weak area can be timely damaged when the battery monomer is out of control due to heat, and the weak area is guaranteed to have enough strength under the normal use condition of the battery monomer.
In some embodiments, 10 μm ≦ S 2 ≤150μm。
In some embodiments, 30 μm ≦ S 2 ≤100μm。
In some embodiments, the minimum thickness of the weakened area is a, satisfying: A/S is more than or equal to 1 1 ≤100。A/S 1 If the thickness of the material is too small, the number of layers of crystal grains in the weak area is less, and the fatigue resistance of the weak area is too small; A/S 1 The thickness direction of the weak area is too large, the number of crystal grain layers in the weak area is too large, the strength of the weak area is too large, and the risk that the weak area cannot be timely damaged when the battery monomer is out of control due to thermal runaway easily occurs. Thus, 1. Ltoreq. A/S 1 On one hand, the number of layers of crystal grains in the thickness direction of the weak area is more, the fatigue resistance of the weak area is improved, and the risk that the weak area is damaged under the normal use condition of the single battery is reduced; on the other hand, the weak area can be damaged more timely when the battery cell is out of control due to heat,so as to achieve the purpose of timely relieving pressure.
In some embodiments, 5 ≦ A/S 1 Less than or equal to 20. The comprehensive performance of the shell part is better, the weak area can be timely damaged when the battery monomer is out of control due to heat, the weak area is guaranteed to have enough anti-fatigue strength under the normal use condition of the battery monomer, and the service life of the battery monomer is prolonged.
In some embodiments, the minimum thickness of the area of weakness is A and the stiffness of the area of weakness is H 1 And satisfies the following conditions: h is less than or equal to 5HBW/mm 1 the/A is less than or equal to 10000HBW/mm. Considering not only the influence of the thickness of the weak region on the performance of the outer shell member but also the influence of the hardness of the weak region on the performance of the outer shell member, 5HBW/mm ≦ H 1 the/A is less than or equal to 10000HBW/mm, so that the weak area has enough strength under the normal use condition of the single battery, the weak area is not easy to be damaged due to fatigue, and the service life of the single battery is prolonged; and the shell part can timely release pressure through the weak area when the battery monomer is out of control due to heat, so that the risk of explosion of the battery monomer is reduced, and the safety of the battery monomer is improved.
In some embodiments, 190HBW/mm ≦ H 1 the/A is less than or equal to 4000HBW/mm. The shell part has better comprehensive performance, and the weak area can be ensured to have enough strength under the normal use condition of the battery monomer under the condition that the weak area can be timely damaged when the battery monomer is out of control due to heat. On the premise of ensuring the safety of the battery monomer, the service life of the battery monomer is prolonged.
In some embodiments, 0.02mm ≦ A ≦ 1.6mm. A is too small, the forming difficulty of the weak area is difficult, and the weak area is easy to damage in the forming process; a is too big, and the difficulty that the weak area is destroyed when the battery monomer is out of control due to heat is increased, so that the situation that the pressure is not released timely is easy to occur. Therefore, A is more than or equal to 0.02mm and less than or equal to 1.6mm, and the pressure relief timeliness of the single battery when thermal runaway is improved under the condition of reducing the forming difficulty of the pressure relief area.
In some embodiments, 0.06mm ≦ A ≦ 0.4mm. Further reducing the molding difficulty of the pressure relief area and improving the pressure relief timeliness of the single battery when the single battery is out of control due to heat.
In some embodiments, the zone of weakness has a stiffness of H 1 Hardness of the non-weakened region is H 2 And satisfies the following conditions: h 1 ＞H 2 . In this way, the rigidity of the weak area is increased, so that the strength of the weak area is increased, and the risk that the weak area is damaged under the normal use condition of the battery cell is reduced.
In some embodiments, H 1 /H 2 ≤5。H 1 /H 2 Too large, the weak area may be difficult to break upon thermal runaway of the cell. Thus, H 1 /H 2 Less than or equal to 5, the risk that the weak area cannot be timely damaged when the thermal runaway of the battery monomer is reduced, and the safety of the battery monomer is improved.
In some embodiments, H 1 /H 2 ≤2.5。
In some embodiments, 5HBW ≦ H 2 ≤150HBW。
In some embodiments, 5HBW ≦ H 1 ≤200HBW。
In some embodiments, the minimum thickness of the weakened area is a and the minimum thickness of the non-weakened area is B, satisfying: A/B is more than or equal to 0.05 and less than or equal to 0.95. If A/B is too small, the strength of the weak area may be insufficient. The A/B is too large, the weak area is not easy to damage when the battery monomer is out of control due to heat, the pressure is not released in time, and the probability of explosion of the battery monomer is increased. Therefore, the A/B is more than or equal to 0.05 and less than or equal to 0.95, the probability of the rupture of the weak area under the normal use condition of the battery monomer can be reduced, and the probability of explosion when the battery monomer is thermally out of control can be reduced.
In some embodiments, 0.12 ≦ A/B ≦ 0.8. Therefore, the comprehensive performance of the external part is better, and the weak area is guaranteed to have enough strength under the normal use condition of the single battery under the condition that the weak area can be timely damaged when the single battery is out of control due to heat.
In some embodiments, 0.2 ≦ A/B ≦ 0.5.
In some embodiments, 0.02mm ≦ A ≦ 1.6mm.
In some embodiments, 0.06mm ≦ A ≦ 0.4mm.
In some embodiments, 1mm ≦ B ≦ 5mm. And B is too large, the thickness of the non-weak area is larger, the material consumption of the shell part is more, the weight of the shell part is large, and the economy is poor. B is too small, the thickness of the non-weakened area is small, and the deformation resistance of the housing part is poor. Therefore, B is more than or equal to 1mm and less than or equal to 5mm, so that the shell part has better economical efficiency and better deformation resistance.
In some embodiments, 1.2mm ≦ B ≦ 3.5mm. So that the housing parts have better economy and resistance to deformation.
In some embodiments, 2mm ≦ B ≦ 3mm.
In some embodiments, the shell part has a vent region, the trough portion comprising a primary scored groove provided along an edge of the vent region, the vent region being configured to be openable bordered by the scored groove, the weakened region forming a bottom of the scored groove. When the weak area is damaged, the pressure relief area can be opened by taking the weak area as a boundary so as to realize pressure relief, and the pressure relief area of the shell part is increased.
In some embodiments, the housing part has a first surface and a second surface arranged opposite to each other, and the score groove is recessed from the first surface in a direction close to the second surface. The marking groove is the groove part, and the structure is simple. When the forming is carried out, the notching groove can be formed on the first surface, the forming is simple, the production efficiency is improved, and the production cost is reduced.
In some embodiments, the outer cover member comprises a first surface and a second surface which are oppositely arranged, the groove portion comprises a plurality of levels of scored grooves which are sequentially arranged on the outer cover member along the direction from the first surface to the second surface, and the weak area is formed at the bottom of the level of scored groove farthest from the first surface; wherein the shell member has a vent region, each stage of score groove being disposed along an edge of the vent region, the vent region being configured to be openable bounded by the stage of score groove furthest from the first surface. When the shell part is formed, the multi-stage notch grooves can be formed on the shell part step by step, and the forming depth of each stage of notch groove can be reduced, so that the forming force of the shell part when each stage of notch groove is formed is reduced, the risk of crack generation of the shell part is reduced, the shell part is not easy to lose efficacy due to crack generation at the position where the notch groove is arranged, and the service life of the shell part is prolonged.
In some embodiments, the primary score groove furthest from the second surface is recessed from the first surface in a direction closer to the second surface. The groove part is composed of multi-stage scoring grooves, and the multi-stage scoring grooves can be gradually processed from the first surface to the second surface during molding.
In some embodiments, the housing member includes a first surface and a second surface disposed opposite to each other, the slot portion further includes a primary countersink recessed from the first surface in a direction toward the second surface, and the pressure relief region is formed in a bottom wall of the countersink. The arrangement of the sinking groove can reduce the depth of the marking groove under the condition of ensuring the thickness of the final weak area to be certain, thereby reducing the molding force applied to the shell part during molding the marking groove and reducing the risk of cracking of the shell part. In addition, the sink groove can provide an avoiding space for the pressure relief area in the opening process, and even if the first surface is shielded by the barrier, the pressure relief area can still be opened for pressure relief.
In some embodiments, the housing member includes a first surface and a second surface disposed opposite to each other, the slot portion further includes a plurality of sunken grooves sequentially disposed on the housing member in a direction from the first surface to the second surface, the first-stage sunken groove farthest from the second surface is recessed from the first surface toward the second surface, and the pressure relief area is formed at a bottom wall of the first-stage sunken groove farthest from the first surface. When multistage heavy groove of shaping, can reduce the shaping degree of depth of each grade heavy groove, the shaping power that the shell part received when can reduce each grade heavy groove of shaping reduces the risk that the shell part produced the crackle. In addition, the multistage sink can provide the space of dodging for the pressure release district in the opening process, even if the first surface is sheltered from by the barrier, the pressure release district still can open the pressure release.
In some embodiments, the interior space of the sink is a cylinder, prism, frustum, or frustum of a prism. The sink groove with the structure is simple in structure and easy to form, and can provide more avoiding spaces for the pressure relief area in the opening process.
In some embodiments, the score groove includes a first groove segment and a second groove segment, the first groove segment intersecting the second groove segment, the first groove segment and the second groove segment being disposed along an edge of the pressure relief zone. The stress is more concentrated at the intersection of the first and second groove segments so that the weakened area can be first broken at the intersection of the first and second groove segments. Under the condition that the detonation pressure of the battery monomer is certain, the weak area can be made thicker, and the forming depth of the notching groove is reduced.
In some embodiments, the score groove further comprises a third groove segment, the first groove segment and the third groove segment are oppositely disposed, the second groove segment intersects the third groove segment, and the first groove segment, the second groove segment, and the third groove segment are disposed along an edge of the pressure relief zone. Therefore, the pressure release area can be opened by taking the first groove section, the second groove section and the third groove section as boundaries, and when the single battery is subjected to pressure release, the pressure release area is opened more easily, so that large-area pressure release of the shell part is realized.
In some embodiments, the first vat segment, the second vat segment and the third vat segment are connected in series, the first vat segment, the second vat segment and the third vat segment defining a pressure relief zone.
In some embodiments, the first, second and third trough sections define two pressure relief zones, one on each side of the second trough section. The two pressure relief areas can be opened in a split mode to relieve pressure, and the pressure relief efficiency of the shell part can be effectively improved.
In some embodiments, the scored groove is a groove extending along a non-closed track. The pressure relief area can be opened in a reversed manner and is eventually connected to other areas of the shell part after opening, reducing the risk of splashing after opening.
In some embodiments, the score groove is a circular arc groove. The arc-shaped groove has simple structure and is easy to form. During the pressure relief process, the pressure relief area can be rapidly broken along the circular arc-shaped groove, so that the pressure relief area can be rapidly opened.
In some embodiments, the scored groove is a groove extending along the closed track. In the pressure relief process, the shell part can be broken along the scored groove, so that the pressure relief area of the shell part can be opened in a breaking-away mode, the pressure relief area of the shell part is increased, and the pressure relief rate of the shell part is improved.
In some embodiments, the score groove is an annular groove. The annular groove is simple in structure and easy to form, and the shell part can be quickly broken along the annular groove in the pressure relief process, so that the pressure relief area can be quickly opened.
In some embodiments, the area of the pressure relief zone is D, satisfying: 90mm 2 ≤D≤1500mm 2 . D is too small, the pressure relief area of the shell part is small, and the pressure relief timeliness is poor when the battery monomer is out of control due to heat; and D is too large, the impact resistance of the pressure relief area is poor, the deformation of the pressure relief area after stress is increased, and the weak area is easily damaged under the normal use condition of the single battery, so that the service life of the single battery is influenced. Therefore, 90mm 2 ≤D≤1500mm 2 The service life of the single battery can be prolonged, and the safety of the single battery can be improved.
In some embodiments, 150mm 2 ≤D≤1200mm 2 。
In some embodiments, 200mm 2 ≤D≤1000mm 2 。
In some embodiments, 250mm 2 ≤D≤800mm 2 。
In some embodiments, the housing member has first and second oppositely disposed surfaces, the well being recessed from the first surface in a direction towards the second surface, the well forming an outer edge at the first surface, the region of the housing member outside the predetermined distance from the outer edge being a non-weakened region. Thus, the non-weakened area is not easily affected during the process of forming the groove portion, so that the crystal grains of the non-weakened area are more uniform.
In some embodiments, the predetermined distance is L, satisfying: l =5mm.
In some embodiments, the shell member further comprises a transition region connecting the weakened region and the non-weakened region, the transition region having an average grain size S 3 And satisfies the following conditions: s 3 ≤S 2 . The transition area has the function of connecting the weak area and the non-weak area, and the weak area and the non-weak area are integrally formed.
In some embodiments, the housing member is an end cap for closing an opening of a case for accommodating the electrode assembly. The end cover has a pressure relief function, and the safety of the battery monomer is guaranteed.
In some embodiments, the housing member is a case having an opening for receiving the electrode assembly. The shell has a pressure relief function, and the safety of the battery monomer is guaranteed.
In some embodiments, the housing includes a plurality of integrally formed walls that collectively define an interior space of the housing, at least one wall being provided with a slot. The plurality of wall portions are integrally formed, so that the wall portion provided with the groove portion has better reliability.
In some embodiments, the plurality of wall portions includes a bottom wall and a plurality of side walls disposed around the bottom wall, the housing forms an opening at an end opposite the bottom wall; the bottom wall is provided with a groove part; and/or at least one side wall is provided with a groove.
In some embodiments, the housing is a cuboid. The battery is suitable for a square battery monomer and can meet the high-capacity requirement of the battery monomer.
In some embodiments, the material of the housing member includes an aluminum alloy. The aluminum alloy housing parts are light in weight, have good ductility, and are easy to mold.
In some embodiments, the aluminum alloy comprises the following components in percentage by mass: more than or equal to 99.6 percent of aluminum, less than or equal to 0.05 percent of copper, less than or equal to 0.35 percent of iron, less than or equal to 0.03 percent of magnesium, less than or equal to 0.03 percent of manganese, less than or equal to 0.25 percent of silicon, less than or equal to 0.03 percent of titanium, less than or equal to 0.05 percent of vanadium, less than or equal to 0.05 percent of zinc and less than or equal to 0.03 percent of other single elements. The aluminum alloy has lower hardness and better forming capability, reduces the forming difficulty of the groove part, improves the forming precision of the groove part and improves the pressure relief consistency of the shell part.
In some embodiments, the aluminum alloy comprises the following components in percentage by mass: more than or equal to 96.7 percent of aluminum, more than or equal to 0.05 percent and less than or equal to 0.2 percent of copper, less than or equal to 0.7 percent of iron, less than or equal to 1.5 percent of manganese, less than or equal to 0.6 percent of silicon, less than or equal to 0.1 percent of zinc, less than or equal to 0.05 percent of other single element components, and less than or equal to 0.15 percent of other total element components. The shell part made of the aluminum alloy has higher hardness, high strength and good anti-damage capability.
In a second aspect, embodiments of the present application provide a battery cell including a housing part provided in any one of the embodiments of the first aspect.
In some embodiments, the battery cell further includes a case having an opening for accommodating the electrode assembly; the housing part is an end cap which closes the opening.
In some embodiments, the housing member is a case having an opening for accommodating the electrode assembly; the battery cell also includes an end cap that closes the opening.
In a third aspect, an embodiment of the present application provides a battery, including the battery cell provided in any one of the embodiments of the second aspect.
In some embodiments, the weakened area is located at a lower portion of the battery cell. In the use process of the battery, under the action of gravity of an electrode assembly, electrolyte and the like in the battery monomer, the weak area can receive larger acting force, and the weak area and the non-weak area are of an integrally formed structure, so that the battery has good structural strength, better reliability and longer service life of the battery monomer.
In some embodiments, the battery cell includes a case for accommodating the electrode assembly, the case including a bottom wall and a plurality of side walls surrounding the bottom wall, the bottom wall being integrally formed with the side walls, the case forming an opening at an end opposite to the bottom wall, and the weak region being located at the bottom wall.
In some embodiments, the battery cell includes an end cap for closing an opening of a case for receiving the electrode assembly, the weakened section being located at the end cap.
In a fourth aspect, an embodiment of the present application provides an electric device, including the battery provided in any one of the embodiments of the third aspect.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained from the drawings without inventive effort.
FIG. 1 is a schematic illustration of a vehicle according to some embodiments of the present application;
fig. 2 is an exploded view of a battery provided in accordance with some embodiments of the present application;
fig. 3 is an exploded view of a battery cell provided in some embodiments of the present application;
FIG. 4 is a schematic structural view of a housing part provided in accordance with some embodiments of the present application;
FIG. 5 is a C-C cross-sectional view of the housing part shown in FIG. 4;
FIG. 6 is a die view (schematic) of the housing part shown in FIG. 5;
fig. 7 is a partial enlarged view of the housing part shown in fig. 5 at E;
FIG. 8 is an enlarged partial view of a housing component provided in accordance with further embodiments of the present application;
FIG. 9 is a schematic view of a structure of a housing part according to further embodiments of the present application (showing a primary score groove);
FIG. 10 is a cross-sectional view E-E of the housing part shown in FIG. 9;
FIG. 11 is a schematic view of a construction of a housing part according to further embodiments of the present application (showing a primary score groove);
FIG. 12 is a sectional view F-F of the housing part shown in FIG. 11;
FIG. 13 is a schematic view of a structure of an enclosure component provided in accordance with further embodiments of the present application (showing a primary score groove);
FIG. 14 is a sectional view taken along line G-G of the housing part shown in FIG. 13;
FIG. 15 is a schematic structural view of a housing part provided in accordance with further embodiments of the present application (showing two-stage scoring grooves);
FIG. 16 is a K-K cross-sectional view of the housing part shown in FIG. 15;
FIG. 17 is a schematic structural view of a housing part provided in accordance with further embodiments of the present application (showing two-stage scoring);
FIG. 18 is a cross-sectional view M-M of the housing part shown in FIG. 17;
FIG. 19 is a schematic structural view of a housing part provided in accordance with further embodiments of the present application (showing two-stage scoring);
fig. 20 is an N-N cross-sectional view of the housing part shown in fig. 19;
fig. 21 is an isometric view of a housing component provided in accordance with some embodiments of the present application;
FIG. 22 is a schematic structural view of the shell member shown in FIG. 21 (showing the primary scored groove and the primary countersunk groove);
FIG. 23 is an O-O cross-sectional view of the housing part shown in FIG. 22;
FIG. 24 is a schematic structural view of a housing component provided in accordance with still further embodiments of the present application (showing a primary scored groove and a primary countersunk groove);
fig. 25 is a P-P sectional view of the housing part shown in fig. 24;
FIG. 26 is a schematic structural view of a housing component provided in accordance with further embodiments of the present application (showing a primary scored groove and a primary countersunk groove);
fig. 27 is a Q-Q sectional view of the housing part shown in fig. 26;
FIG. 28 is a schematic structural view of an enclosure component provided in accordance with certain embodiments of the present application (showing one-stage scored grooves and two-stage countersunk grooves);
fig. 29 is an R-R sectional view of the housing part shown in fig. 28;
FIG. 30 is a schematic structural view of a housing component provided in accordance with still further embodiments of the present application (showing one-stage scored grooves and two-stage countersunk grooves);
FIG. 31 is an S-S cross-sectional view of the housing part shown in FIG. 30;
FIG. 32 is a schematic structural view of an outer shell component provided in accordance with further embodiments of the present application (showing one-stage scored grooves and two-stage countersunk grooves);
FIG. 33 is a cross-sectional T-T view of the housing part shown in FIG. 32;
FIG. 34 is a schematic structural view of an outer jacket component provided in accordance with some embodiments of the present disclosure (showing a primary score groove, the score groove being V-shaped);
FIG. 35 is a schematic view of a housing part according to another embodiment of the present application;
FIG. 36 is a die view (schematic view) of a housing component according to further embodiments of the present application;
FIG. 37 is a schematic structural view of an end cap provided in accordance with some embodiments of the present application;
FIG. 38 is a schematic structural view of a housing provided in accordance with some embodiments of the present application;
FIG. 39 is a schematic illustration of a housing according to further embodiments of the present application;
fig. 40 is a schematic structural diagram of a battery cell according to some embodiments of the present disclosure.
Icon: 1-a housing; 11-end cap; 12-a housing; 121-a wall portion; 121 a-side wall; 121 b-bottom wall; 2-an electrode assembly; 21-positive tab; 22-negative tab; 3-a positive electrode terminal; 4-a negative electrode terminal; 5-a housing part; 51-non-weakened areas; 511-inner edge; 52-a zone of weakness; 53-a trough portion; 531-the bottom surface of the groove; 532-notching groove; 532 a-the outermost primary notching groove; 532 b-innermost primary score groove; 5321-a first trough section; 5322-a second trough section; 5323-a third channel section; 533-sink tank; 533 a-the outermost primary sink; 533 b-the innermost primary sink; 5331-bottom wall of sink tank; 534-outer edge; 54-a first surface; 55-a second surface; 56-pressure relief area; a 57-transition zone; 10-a battery cell; 20-a box body; 201-a first portion; 202-a second portion; 100-a battery; 200-a controller; 300-a motor; 1000-a vehicle; y-mid-plane.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the description of the application in the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "including" and "having," and any variations thereof, in the description and claims of this application and the description of the above figures are intended to cover non-exclusive inclusions. The terms "first," "second," and the like in the description and claims of this application or in the foregoing drawings are used for distinguishing between different elements and not for describing a particular sequential or chronological order.
Reference in the specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the specification. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.
The term "and/or" in this application is only one kind of association relationship describing the associated object, and means that there may be three kinds of relationships, for example, a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" in this application generally indicates that the preceding and following associated objects are in an "or" relationship.
In the embodiments of the present application, like reference numerals denote like components, and in the different embodiments, detailed descriptions of the like components are omitted for the sake of brevity. It should be understood that the thickness, length, width and other dimensions of the various components in the embodiments of the present application and the overall thickness, length, width and other dimensions of the integrated device shown in the drawings are only illustrative and should not constitute any limitation to the present application.
The appearances of "a plurality" in this application are intended to mean more than two (including two).
In the embodiment of the present application, the battery cell may be a secondary battery, and the secondary battery refers to a battery cell that can be continuously used by activating an active material through a charging manner after the battery cell is discharged.
The battery cell may be a lithium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead storage battery, and the like, which is not limited in this application.
The battery referred to in embodiments of the present application may include one or more battery cells to provide a single physical module of higher voltage and capacity. When there are a plurality of battery cells, the plurality of battery cells are connected in series, in parallel, or in series-parallel by the bus member.
In some embodiments, the battery may be a battery module, and when there are a plurality of battery cells, the plurality of battery cells are arranged and fixed to form one battery module.
In some embodiments, the battery may be a battery pack including a case and a battery cell, and the battery cell or the battery module is received in the case.
In some embodiments, the tank may be part of the chassis structure of the vehicle. For example, portions of the box may become at least a portion of a floor of the vehicle, or portions of the box may become at least a portion of a cross member and a side member of the vehicle.
In some embodiments, the battery may be an energy storage device. The energy storage device comprises an energy storage container, an energy storage electric cabinet and the like.
The development of battery technology requires consideration of various design factors, such as energy density, cycle life, discharge capacity, charge/discharge rate, and other performance parameters, as well as battery safety.
In single battery, for guaranteeing single battery's security, can set up pressure release mechanism on single battery's shell, when single battery thermal runaway, through the inside pressure of pressure release mechanism release single battery to improve single battery's security.
For a typical cell, the pressure relief mechanism is welded to the housing to secure the pressure relief mechanism to the housing. Taking the pressure relief mechanism as an explosion-proof sheet arranged on the end cover of the shell as an example, when the single battery is out of control due to heat, the explosion-proof sheet is damaged so as to discharge the emissions in the single battery, thereby achieving the purpose of releasing the pressure in the single battery. Because pressure relief mechanism and shell welded connection, the welding position can appear the crackle in battery monomer long-term use in-process, leads to welding position's intensity to reduce, appears easily that the welding position is destroyed when the pressure of battery monomer inside does not reach pressure relief mechanism's detonation pressure, leads to pressure relief mechanism to become invalid, and pressure relief mechanism's reliability is lower.
In order to improve the reliability of the pressure relief mechanism, the inventor has found that the pressure relief mechanism and the housing may be formed as an integral structure, that is, a part of the housing is used as the pressure relief mechanism. For example, the local part of the end cover is weakened, so that the local strength of the end cover is reduced, a weak area is formed, and an integrated pressure relief mechanism is formed, and therefore the reliability of the pressure relief mechanism can be effectively improved.
The inventor notices that after the integrated pressure relief mechanism is formed on the shell, the mechanical property of the weak area of the shell is poor, and under the normal use condition of the single battery, the weak area is easy to be damaged due to fatigue caused by long-term change of the internal pressure of the single battery, so that the service life of the single battery is influenced.
In view of this, the embodiments of the present application provide a case member in which a non-weak area and a weak area are formed integrally by providing a groove portion on a case member, the non-weak area being formed around the groove portion, the weak area being formed at a bottom of the groove portion, and an average grain size of the weak area being S 1 The average grain size of the non-weakened region is S 2 ，S 1 /S 2 ≤0.9。
In such a housing part, S 1 /S 2 Less than or equal to 0.9, reduces the average grain size of the weak area, improves the mechanical property of the material of the weak area, improves the toughness and the fatigue resistance of the weak area, reduces the risk that the weak area is damaged under the normal use condition of the battery monomer, and improves the service life of the battery monomer.
The technical scheme described in the embodiment of the application is suitable for the battery and the electric equipment using the battery.
The electric equipment can be vehicles, mobile phones, portable equipment, notebook computers, ships, spacecrafts, electric toys, electric tools and the like. The vehicle can be a fuel oil vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle or a range extending vehicle and the like; spacecraft include aircraft, rockets, space shuttles, spacecraft, and the like; the electric toys include stationary or mobile electric toys, such as game machines, electric car toys, electric ship toys, electric airplane toys, and the like; the electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and electric tools for railways, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, electric impact drills, concrete vibrators, and electric planers. The embodiment of the present application does not particularly limit the above electric devices.
For convenience of explanation, the following embodiments will be described by taking an electric device as an example of a vehicle.
Referring to fig. 1, fig. 1 is a schematic structural diagram of a vehicle 1000 according to some embodiments of the present disclosure. The battery 100 is provided inside the vehicle 1000, and the battery 100 may be provided at the bottom or the head or the tail of the vehicle 1000. The battery 100 may be used for power supply of the vehicle 1000, for example, the battery 100 may serve as an operation power source of the vehicle 1000.
The vehicle 1000 may further include a controller 200 and a motor 300, the controller 200 being configured to control the battery 100 to supply power to the motor 300, for example, for starting, navigation, and operational power requirements while the vehicle 1000 is traveling.
In some embodiments of the present application, the battery 100 may not only serve as an operating power source of the vehicle 1000, but also serve as a driving power source of the vehicle 1000, instead of or in part of fuel or natural gas, to provide driving power for the vehicle 1000.
Referring to fig. 2, fig. 2 is an exploded view of a battery 100 according to some embodiments of the present disclosure. The battery 100 includes a battery cell 10 and a case 20, and the case 20 accommodates the battery cell 10.
The case 20 is a component for accommodating the battery cell 10, the case 20 provides a placement space for the battery cell 10, and the case 20 may have various structures. In some embodiments, the case 20 may include a first portion 201 and a second portion 202, and the first portion 201 and the second portion 202 are covered with each other to define a placement space for receiving the battery cell 10. The first portion 201 and the second portion 202 may be in various shapes, such as a rectangular parallelepiped, a cylinder, and the like. The first part 201 may be a hollow structure with one side open, the second part 202 may also be a hollow structure with one side open, and the open side of the second part 202 is closed to the open side of the first part 201, so as to form the box body 20 with a placing space. The first portion 201 may have a hollow structure with one side open, the second portion 202 may have a plate-like structure, and the second portion 202 may cover the open side of the first portion 201 to form the case 20 having a storage space. As an example, the battery cell 10 may be a cylindrical battery cell, a prismatic battery cell including a square-can battery cell, a blade-shaped battery cell, a polygonal battery cell such as a hexagonal prism battery, or other shaped battery cell 10, and the present application is not particularly limited.
In the battery 100, one or more battery cells 10 may be provided. If there are a plurality of battery cells 10, the plurality of battery cells 10 may be connected in series, in parallel, or in series-parallel, where in series-parallel refers to that the plurality of battery cells 10 are connected in series or in parallel. A plurality of battery cells 10 may be connected in series, in parallel, or in series-parallel to form a battery module, and a plurality of battery modules may be connected in series, in parallel, or in series-parallel to form a whole, and may be accommodated in the case 20. All the single batteries 10 can also be directly connected in series or in parallel or in series-parallel, and the whole formed by all the single batteries 10 is accommodated in the box body 20.
Referring to fig. 3, fig. 3 is an exploded view of a battery cell 10 according to some embodiments of the present disclosure. The battery cell 10 may include a case 1 and an electrode assembly 2.
The case 1 accommodates the electrode assembly 2, an electrolyte, and the like. The shell 1 can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell) or an aluminum-plastic film and the like. As an example, the housing 1 may include a case 12 and an end cap 11.
The housing 12 may be a hollow structure with one end open, or the housing 12 may be a hollow structure with opposite ends open. The material of the housing 12 may be various, such as copper, iron, aluminum, steel, aluminum alloy, etc.
The end cap 11 is a member that closes the opening of the case 12 to isolate the internal environment of the battery cell 10 from the external environment. The end cap 11 and the case 12 together define a receiving space for receiving the electrode assembly 2, the electrolyte, and other components. The end cap 11 may be attached to the housing 12 by welding or crimping to close the opening of the housing 12. The shape of the end cap 11 may be adapted to the shape of the casing 1, for example, the housing 12 is a rectangular parallelepiped structure, the end cap 11 is a rectangular plate structure adapted to the casing 1, and for example, the housing 12 is a cylinder, and the end cap 11 is a circular plate structure adapted to the housing 12. The end cap 11 may be made of various materials, such as copper, iron, aluminum, steel, aluminum alloy, etc.
In the battery cell 10, the number of the end caps 11 may be one or two. In the embodiment that the housing 12 is a hollow structure with openings formed at two ends, two end covers 11 may be correspondingly disposed, the two end covers 11 respectively close the two openings of the housing 12, and the two end covers 11 and the housing 12 together define an accommodating space. In the embodiment that the housing 12 is a hollow structure with an opening formed at one end, one end cover 11 may be correspondingly arranged, the end cover 11 closes the opening at one end of the housing 12, and one end cover 11 and the housing 12 jointly define a containing space.
The electrode assembly 2 includes a positive electrode, a negative electrode, and a separator. During charge and discharge of the battery cell 10, active ions (e.g., lithium ions) are inserted and extracted back and forth between the positive electrode and the negative electrode. The separator is arranged between the anode and the cathode, can play a role in preventing the short circuit of the anode and the cathode, and can allow active ions to pass through.
In some embodiments, the positive electrode may be a positive electrode tab, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.
As an example, the positive electrode current collector has two surfaces opposite in its own thickness direction, and the positive electrode active material is disposed on either or both of the two surfaces opposite to the positive electrode current collector.
As an example, the positive electrode current collector may employ a metal foil or a composite current collector. For example, as the metal foil, aluminum or stainless steel surface-treated with silver, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, titanium, or the like can be used. The composite current collector may include a polymeric material base layer and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel alloy, titanium alloy, silver alloy, etc.) on a base material of a polymer material (e.g., a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).
As an example, the positive electrode active material may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. However, the present application is not limited to these materials, and other conventional materials that can be used as a positive electrode active material of a battery may be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium-containing phosphates may include, but are not limited to, lithium iron phosphate (e.g., liFePO) 4 (also referred to as LFP for short)), a composite material of lithium iron phosphate and carbon, and lithium manganese phosphate (e.g., liMnPO) 4 ) At least one of a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon. Examples of the lithium transition metal oxide may include, but are not limited to, lithium cobalt oxide (e.g., liCoO) 2 ) Lithium nickel oxide (e.g., liNiO) 2 ) Lithium manganese oxide (e.g., liMnO) 2 、LiMn2O 4 ) Lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (e.g., liNi) 1/3 Co 1/3 Mn 1/3 O 2 (may also be abbreviated as NCM) 333 )、LiNi 0.5 Co 0.2 Mn 0.3 O 2 (may also be abbreviated as NCM) 523 )、LiNi 0.5 Co 0.25 Mn 0.25 O 2 (may also be abbreviated as NCM) 211 )、LiNi 0.6 Co 0.2 Mn 0.2 O 2 (may also be abbreviated as NCM) 622 )、LiNi 0.8 Co 0.1 Mn 0.1 O 2 (may also be abbreviated as NCM) 811 ) Lithium nickel cobalt aluminum oxides (e.g., liNi) 0.85 Co 0.15 Al 0.05 O 2 ) And modified compounds thereof, and the like.
In some embodiments, the positive electrode may employ a metal foam. The foam metal can be foam nickel, foam copper, foam aluminum, foam alloy, foam carbon, or the like. When the metal foam is used as the positive electrode, the surface of the metal foam may not be provided with the positive electrode active material, and the positive electrode active material may be provided. By way of example, a lithium source material, potassium metal or sodium metal, may also be filled and/or deposited within the metal foam, the lithium source material being lithium metal and/or a lithium rich material.
In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.
As an example, the negative electrode current collector has two surfaces opposite in its own thickness direction, and the negative electrode active material is disposed on either or both of the two surfaces opposite to the negative electrode current collector.
As an example, the negative electrode current collector may employ a metal foil or a composite current collector. For example, as the metal foil, aluminum or stainless steel surface-treated with silver, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, titanium, or the like can be used. The composite current collector may include a polymeric material base layer and a metal layer. The composite current collector may be formed by forming a metal material (copper, copper alloy, nickel alloy, titanium alloy, silver alloy, etc.) on a base material of a polymer material (e.g., a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).
As an example, a negative active material for a battery known in the art may be used as the negative active material. As an example, the anode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate and the like. The silicon-based material may be selected from at least one of elemental silicon, silicon oxy-compounds, silicon-carbon compounds, silicon-nitrogen compounds, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin-oxygen compounds, and tin alloys. However, the present application is not limited to these materials, and other conventional materials that can be used as a battery negative active material may also be used. These negative electrode active materials may be used alone or in combination of two or more.
In some embodiments, the negative electrode may employ a metal foam. The foam metal can be foam nickel, foam copper, foam aluminum, foam alloy, foam carbon, or the like. When the foamed metal is used as the negative electrode sheet, the surface of the foamed metal may not be provided with the negative electrode active material, and of course, the negative electrode active material may also be provided.
By way of example, a lithium source material, potassium metal, or sodium metal may also be filled and/or deposited within the negative current collector, the lithium source material being lithium metal and/or a lithium rich material.
In some embodiments, the material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.
In some embodiments, the electrode assembly 2 further includes a separator disposed between the positive electrode and the negative electrode.
In some embodiments, the separator is a separator film. The type of the separator is not particularly limited, and any known separator having a porous structure and good chemical and mechanical stability may be used.
As an example, the main material of the isolation film may be at least one selected from glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator may be a single-layer film or a multilayer composite film, and is not particularly limited. When the separator is a multilayer composite film, the materials of the respective layers may be the same or different, and are not particularly limited. The separator may be a single component located between the positive and negative electrodes, or may be attached to the surfaces of the positive and negative electrodes.
In some embodiments, the separator is a solid electrolyte. The solid electrolyte is arranged between the anode and the cathode and plays roles of transmitting ions and isolating the anode and the cathode.
In some embodiments, the battery cell 10 further includes an electrolyte that functions to conduct ions between the positive and negative electrodes. The electrolyte is not particularly limited and may be selected as desired. The electrolyte may be liquid, gel, or solid.
Wherein the liquid electrolyte comprises an electrolyte salt and a solvent.
In some embodiments, the electrolyte salt may be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis-fluorosulfonylimide, lithium bis-trifluoromethanesulfonylimide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalato borate, lithium dioxaoxalato borate, lithium difluorodioxaoxalato phosphate, and lithium tetrafluorooxalato phosphate.
In some embodiments, the solvent may be selected from at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1, 4-butyrolactone, sulfolane, dimethylsulfone, methylethylsulfone, and diethylsulfone. The solvent can also be ether solvent. The ether solvent may include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1, 3-dioxolane, tetrahydrofuran, methyltetrahydrofuran, diphenyl ether, and crown ether.
The gel-state electrolyte comprises a skeleton network which takes a polymer as an electrolyte and is matched with an ionic liquid-lithium salt.
Wherein the solid electrolyte comprises polymer solid electrolyte, inorganic solid electrolyte and composite solid electrolyte.
As examples, the polymer solid electrolyte may be polyether (polyethylene oxide), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, mono-ionic polymer, polyionic liquid-lithium salt, cellulose, and the like.
As examples, the inorganic solid electrolyte may be one or more of an oxide solid electrolyte (crystalline perovskite, sodium super-ionic conductor, garnet, amorphous LiPON thin film), a sulfide solid electrolyte (crystalline lithium super-ionic conductor (lithium \37754, sulfur silver \37754ore), amorphous sulfide), and a halide solid electrolyte, a nitride solid electrolyte, and a hydride solid electrolyte.
As an example, the composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.
In some embodiments, the electrode assembly 2 is in a wound structure. The positive plate and the negative plate are wound into a winding structure.
In some embodiments, the electrode assembly 2 is a laminate structure.
As an example, the positive electrode tab and the negative electrode tab may be respectively provided in plurality, and the plurality of positive electrode tabs and the plurality of negative electrode tabs may be alternately stacked.
As an example, the positive electrode sheet may be provided in plurality, the negative electrode sheet is folded to form a plurality of folded sections arranged in a stacked manner, and one positive electrode sheet is sandwiched between adjacent folded sections.
As an example, the positive and negative electrode tabs are each folded to form a plurality of folded sections arranged in a stack.
As an example, the separator may be provided in plurality, respectively, between any adjacent positive electrode tabs or negative electrode tabs.
As an example, the separator may be continuously disposed, by being folded or wound, between any adjacent positive or negative electrode sheets.
In some embodiments, the electrode assembly 2 may be cylindrical, flat, polygonal, or the like in shape.
In some embodiments, the electrode assembly 2 is provided with tabs that can conduct current away from the electrode assembly 2. The tabs include a positive tab 21 and a negative tab 22.
The battery cell 10 may further include electrode terminals, which may be disposed on the case 1, for electrically connecting with tabs of the electrode assembly 2 to output electric power of the battery cell 10. The electrode terminal and the tab may be directly connected, for example, the electrode terminal and the tab are directly welded. The electrode terminals and the tabs may also be indirectly connected, for example, by a current collecting member. The current collecting member may be a metal conductor, such as copper, iron, aluminum, steel, aluminum alloy, or the like.
As shown in fig. 3, taking a hollow structure with an opening formed at one end of the case 12 as an example, two electrode terminals may be disposed on the end cap 11, the two electrode terminals are a positive electrode terminal 3 and a negative electrode terminal 4, respectively, the positive electrode terminal 3 is electrically connected to the positive tab 21, and the negative electrode terminal 4 is electrically connected to the negative tab 22.
Referring to fig. 4-7, fig. 4 is a schematic structural view of a housing part 5 according to some embodiments of the present application; fig. 5 is a C-C sectional view of the housing part 5 shown in fig. 4; FIG. 6 is a die view (schematic view) of the housing part 5 shown in FIG. 5; fig. 7 is a partially enlarged view of the housing member 5 shown in fig. 5 at E. The embodiment of the present application provides a housing member 5 for a battery cell 10, including a non-weak area 51 and a weak area 52 that are integrally formed, the housing member 5 being provided with a groove portion 53, the non-weak area 51 being formed around the groove portion 53, the weak area 52 being formed at the bottom of the groove portion 53, the weak area 52 being configured to be broken when the battery cell 10 is relieved of internal pressure. Wherein the weakened region 52 has an average grain size S 1 The average grain size of the non-weakened region 51 is S 2 And satisfies the following conditions: s 1 /S 2 ≤0.9。
The case member 5 is a member capable of accommodating the electrode assembly 2 together with other members, the case member 5 is a part of the case 1, the end cap 11 of the case 1 may be the case member 5, or the case 12 of the case 1 may be the case member 5. The case member 5 may be made of a metal material, such as copper, iron, aluminum, steel, aluminum alloy, or the like, and the case member 5 may be an aluminum-plastic film.
The weakened region 52 is a portion of the housing member 5 that is weaker than other regions, and the weakened region 52 of the housing member 5 can be broken to relieve the pressure inside the battery cell 10 when the pressure inside the battery cell 10 reaches a threshold value. The weakened area 52 may be broken by rupture, detachment, or the like. For example, when the internal pressure of the battery cell 10 reaches a threshold value, the weak region 52 is ruptured by the discharge (gas, electrolyte, etc.) inside the battery cell 10, so that the discharge inside the battery cell 10 can be smoothly discharged. The area of weakness 52 may be a variety of shapes, such as rectangular, circular, oval, circular, rounded, U-shaped, H-shaped, and the like. The thickness of the weakened area 52 may or may not be uniform.
The weakened region 52 is formed at the bottom of the groove 53, and the groove 53 can be formed by various methods, for example, the groove 53 can be formed by stamping, milling, laser etching, etc. to form the weakened region 52 and the non-weakened region 51 integrally. After the groove portion 53 is press-molded in the case member 5, the case member 5 is thinned in the region where the groove portion 53 is provided, and the weak area 52 is correspondingly formed. The groove 53 may be a primary groove, and the groove side surface of the groove 53 is continuous in the depth direction of the groove 53, for example, the groove 53 may be a groove having a rectangular parallelepiped, a pillar, or the like as an internal space. The groove portion 53 may also be a multi-stage groove arranged along the depth direction of the groove portion 53, in adjacent two-stage grooves, the inner (deeper position) one-stage groove is provided on the groove bottom surface of the outer (shallower position) one-stage groove, for example, the groove portion 53 is a stepped groove. In molding, a multi-step groove may be press-molded stepwise in the depth direction of the groove portion 53, and the weak region 52 is formed at the bottom of the one-step groove located at the deepest position (innermost) among the multi-step grooves.
The non-weak area 51 is formed around the groove portion 53, the strength of the non-weak area 51 is greater than that of the weak area 52, and the weak area 52 is more easily broken than the non-weak area 51. When the groove portion 53 is formed in the case member 5 by punching, the non-weakened area 51 may be a portion of the case member 5 that is not punched. The thickness of the non-weakened areas 51 may or may not be uniform.
The average grain size can be measured by the intercept method in GB 6394-2017, which is not described herein. In measuring the average grain size of the weak region 52, the measurement may be performed in the thickness direction of the weak region 52; in measuring the average grain size of the non-weakened region 51, the measurement may be performed in the thickness direction of the non-weakened region 51.
In fig. 5, the thickness direction of the weakened area 52 coincides with the thickness direction of the non-weakened area 51, and both directions are Z-direction.
S 1 /S 2 May be any one of 0.01, 0.03, 0.04, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, or a range between any two.
In the embodiments of the present application, the weakened zone52 and the non-weakened area 51 are integrally formed, the reliability of the housing member 5 is higher. Due to S 1 /S 2 The average grain size of the weak area 52 is less than or equal to 0.9, the difference between the average grain size of the weak area 52 and the average grain size of the non-weak area 51 is larger, the average grain size of the weak area 52 is reduced, the purpose of refining the grains of the weak area 52 is achieved, the mechanical property of the material of the weak area 52 is improved, the toughness and the fatigue resistance of the weak area 52 are improved, the risk that the weak area 52 is damaged under the normal use condition of the single battery 10 is reduced, and the service life of the single battery 10 is prolonged.
In some embodiments, S 1 /S 2 ≥0.05。
The inventors noted that when S 1 /S 2 When the pressure is less than 0.05, the difficulty of forming the weak area 52 is increased, the strength of the weak area 52 is too high, the difficulty of damaging the weak area 52 when the battery monomer 10 is in thermal runaway is increased, and the situation that the pressure release is not timely is easy to occur.
Thus, S 1 /S 2 Not less than 0.05, the forming difficulty of the forming weak area 52 is reduced, and the pressure relief timeliness of the single battery 10 in thermal runaway is improved.
In some embodiments, 0.1 ≦ S 1 /S 2 ≤0.5。
S 1 /S 2 May be any one of 0.1, 0.12, 0.15, 0.17, 0.2, 0.22, 0.25, 0.27, 0.3, 0.32, 0.35, 0.37, 0.4, 0.42, 0.45, 0.47, 0.5, or a range between any two.
In the present embodiment, 0.1. Ltoreq.S 1 /S 2 Less than or equal to 0.5, so that the comprehensive performance of the shell part 5 is better, and the weak area 52 is ensured to have enough strength under the normal use condition of the single battery 10 under the condition that the weak area 52 can be timely damaged when the single battery 10 is in thermal runaway.
In some embodiments, 0.4 μm ≦ S 1 ≤75μm。
S 1 Can be any one of 0.4 μm, 0.5 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 28 μm, 30 μm, 35 μm, 36 μm, 40 μm, 45 μm, 49 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 72 μm, 75 μmOr any range value therebetween.
The inventors noted that S 1 More than 75 mu m, and the toughness and the fatigue resistance of the weak area 52 are poor; s 1 Less than 0.4mm, the forming difficulty of the weak area 52 is high, the strength of the weak area 52 is too high, the difficulty that the weak area 52 is damaged when the battery monomer 10 is out of control due to heat is increased, and the situation that pressure release is not timely is easy to occur.
Therefore, 0.1 μm. Ltoreq.S 1 The thickness is less than or equal to 75 mu m, on one hand, the forming difficulty of the weak area 52 is reduced, and the pressure relief timeliness of the single battery 10 in thermal runaway is improved; on the other hand, the toughness and fatigue resistance of the weak region 52 are improved, and the risk of the weak region 52 being damaged under normal use conditions of the battery cell 10 is reduced.
In some embodiments, 1 μm ≦ S 1 ≤10μm。
S 1 May be any one of 1 μm, 1.5 μm, 1.6 μm, 2 μm, 2.5 μm, 2.6 μm, 3 μm, 3.5 μm, 3.6 μm, 4 μm, 4.5 μm, 4.6 μm, 5 μm, 5.5 μm, 5.6 μm, 6 μm, 6.5 μm, 6.6 μm, 7 μm, 7.5 μm, 7.6 μm, 8 μm, 8.5 μm, 8.6 μm, 9 μm, 9.5 μm, 9.6 μm, 10 μm, or a range between any two of them.
In this embodiment, 1 μm. Ltoreq.S 1 Less than or equal to 10 mu m, so that the comprehensive performance of the shell part 5 is better, and the weak area 52 is ensured to have enough strength under the normal use condition of the battery monomer 10 under the condition that the weak area 52 can be damaged in time when the battery monomer 10 is in thermal runaway.
In some embodiments, 10 μm ≦ S 2 ≤150μm。
S 2 Any one or a range between 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85 μm, 90 μm, 95 μm, 100 μm, 105 μm, 110 μm, 115 μm, 120 μm, 125 μm, 130 μm, 135 μm, 140 μm, 145 μm, 150 μm may be used.
In some embodiments, 30 μm ≦ S 2 ≤100μm。
S 2 Can be 30 μm, 32 μm, 35 μm, 37 μmAny one of values or ranges between any two of 40 μm, 42 μm, 45 μm, 47 μm, 50 μm, 52 μm, 55 μm, 57 μm, 60 μm, 62 μm, 65 μm, 67 μm, 70 μm, 72 μm, 75 μm, 77 μm, 80 μm, 82 μm, 85 μm, 87 μm, 90 μm, 92 μm, 95 μm, 97 μm, 100 μm.
In some embodiments, the minimum thickness of the weakened area 52 is a, satisfying: A/S is more than or equal to 1 1 ≤100。
A/S 1 May be any one of 1, 2, 4, 5, 10, 15, 20, 21, 22, 23, 25, 30, 33, 34, 35, 37, 38, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 93, 94, 95, 100 point values or ranges between any two.
When A/S 1 If <1, the smaller the number of crystal grain layers in the weak region 52 in the thickness direction of the weak region 52, the too small fatigue resistance of the weak region 52; when A/S 1 When the thickness of the weak region 52 is greater than 100, the number of the crystal grain layers of the weak region 52 is too large in the thickness direction of the weak region 52, and the strength of the weak region 52 is too high, so that the weak region 52 is easily damaged in time when the thermal runaway of the battery cell 10 occurs.
Thus, 1. Ltoreq. A/S 1 On one hand, the number of layers of crystal grains in the thickness direction of the weak area 52 is more, the fatigue resistance of the weak area 52 is improved, and the risk that the weak area 52 is damaged under the normal use condition of the single battery 10 is reduced; on the other hand, the weak area 52 can be damaged more timely when the battery cell 10 is out of control due to heat, so as to achieve the purpose of timely pressure relief.
In some embodiments, 5 ≦ A/S 1 ≤20。
A/S 1 May be any one or a range between any two of 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5, 15, 15.5, 16, 16.5, 17, 17.5, 18, 18.5, 19, 19.5, 20.
In this embodiment, 5. Ltoreq.A/S 1 Less than or equal to 20, so that the comprehensive performance of the shell part 5 is better, the weak area 52 can be timely damaged when the single battery 10 is in thermal runaway, and the weak area 52 can be ensured to be in the batteryThe single body 10 has sufficient fatigue resistance under normal use conditions, and the service life of the battery single body 10 is prolonged.
In some embodiments, the minimum thickness of the area of weakness 52 is A and the stiffness of the area of weakness 52 is H 1 And satisfies the following conditions: h is not more than 5HBW/mm 1 /A≤10000HBW/mm。
H 1 the/A may be any one of 5HBW/mm, 6HBW/mm, 7HBW/mm, 20HBW/mm, 50HBW/mm, 61HBW/mm, 62HBW/mm, 63HBW/mm, 64HBW/mm, 75HBW/mm, 90HBW/mm, 100HBW/mm, 120HBW/mm, 150HBW/mm, 190HBW/mm, 500HBW/mm, 1000HBW/mm, 1200HBW/mm, 1750HBW/mm, 1800HBW/mm, 2100HBW/mm, 4000HBW/mm, 5000HBW/mm, 8000HBW/mm, 9000HBW/mm, 10000HBW/mm, or a range between any two.
The hardness of the weakened area 52 is brinell hardness in HBW. The measurement method of Brinell hardness can be implemented by referring to the measurement principle in GB/T23.1-2018. In actual measurement, the hardness of the weak area 52 may be measured on the inner surface or the outer surface in the thickness direction of the weak area 52. Taking the case member 5 as the end cap 11 of the battery cell 10 as an example, the hardness of the weak region 52 may be measured on the outer surface of the weak region 52 facing away from the inside of the battery cell 10, and the hardness of the weak region 52 may also be measured on the inner surface of the weak region 52 facing the inside of the battery cell 10.
When H is present 1 At a > 10000HBW/mm, the weakened region 52 is thin and has a high hardness, which results in that the weakened region 52 is very fragile, the weakened region 52 is easily damaged under normal use conditions of the battery cell 10, and the service life of the battery cell 10 is short. When H is present 1 When the/A is less than 5HBW/mm, the weak area 52 is thick and has low hardness, and when the single battery 10 is out of control due to heat, the weak area 52 can be stretched and expanded, so that the pressure relief timeliness is poor.
In the present embodiment, 5HBW/mm ≦ H in consideration of not only the influence of the thickness of the weak region 52 on the performance of the case member 5 but also the influence of the hardness of the weak region 52 on the performance of the case member 5 1 the/A is less than or equal to 10000HBW/mm, the weak area 52 has enough strength under the normal use condition of the single battery 10, the weak area 52 is not easy to be damaged due to fatigue, and the quality of the single battery 10 is improvedThe service life is prolonged; and the shell part 5 can be timely decompressed through the weak area 52 when the single battery 10 is out of control due to heat, so that the risk of explosion of the single battery 10 is reduced, and the safety of the single battery 10 is improved.
In some embodiments, 190HBW/mm ≦ H 1 /A≤4000HBW/mm。
H 1 the/A may be any one of 190HBW/mm, 250HBW/mm, 280HBW/mm, 300HBW/mm, 350HBW/mm, 400HBW/mm, 450HBW/mm, 500HBW/mm, 600HBW/mm, 700HBW/mm, 875HBW/mm, 1000HBW/mm, 1200HBW/mm, 1500HBW/mm, 1750HBW/mm, 1800HBW/mm, 2000HBW/mm, 2100HBW/mm, 2500HBW/mm, 3000HBW/mm, 3500HBW/mm, 4000HBW/mm, or a range between any two.
In this embodiment, 190HBW/mm ≦ H 1 the/A is less than or equal to 4000HBW/mm, so that the shell part 5 has better comprehensive performance, and the weak area 52 has enough strength under the normal use condition of the single battery 10 under the condition that the weak area 52 can be timely damaged when the single battery 10 is in thermal runaway. On the premise of ensuring the safety of the battery cell 10, the service life of the battery cell 10 is prolonged.
In some embodiments, 0.02mm ≦ A ≦ 1.6mm.
A may be any one of 0.02mm, 0.04mm, 0.05mm, 0.06mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, 0.7mm, 0.75mm, 0.8mm, 0.85mm, 0.9mm, 0.95mm, 1mm, 1.05mm, 1.1mm, 1.15mm, 1.2mm, 1.25mm, 1.3mm, 1.35mm, 1.4mm, 1.42mm, 1.43mm, 1.45mm, 1.47mm, 1.5mm, 1.55mm, 1.6mm or a range between any two of the foregoing.
When A is less than 0.02mm, the forming difficulty of the weak area 52 is difficult, and the weak area 52 is easily damaged in the forming process; when A is larger than 1.6mm, the difficulty that the weak area 52 is damaged when the battery monomer 10 is out of control due to heat is increased, and the situation that pressure relief is not timely is easy to occur.
Therefore, A is more than or equal to 0.02mm and less than or equal to 1.6mm, and the pressure relief timeliness of the single battery 10 in thermal runaway is improved under the condition of reducing the molding difficulty of the pressure relief area 56.
In some embodiments, 0.06mm ≦ A ≦ 0.4mm.
A may be any one of 0.06mm, 0.07mm, 0.08mm, 0.1mm, 0.15mm, 0.18mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, or a range between any two.
In the embodiment, A is more than or equal to 0.06mm and less than or equal to 0.4mm, so that the forming difficulty of the weak region 52 is further reduced, and the pressure relief timeliness of the single battery 10 in thermal runaway is improved.
In some embodiments, the area of weakness 52 has a stiffness of H 1 The non-weakened region 51 has a hardness of H 2 And satisfies the following conditions: h 1 ＞H 2 。
The hardness of the non-weakened areas 51 is brinell hardness in HBW units. In the actual measurement process, the hardness of the non-weakened area 51 may be obtained by measurement of the inner surface or the outer surface in the thickness direction of the non-weakened area 51. Taking the case member 5 as the end cap 11 of the battery cell 10 as an example, the hardness of the non-weakened region 51 may be measured on an outer surface of the non-weakened region 51 facing away from the inside of the battery cell 10, and the hardness of the non-weakened region 51 may also be measured on an inner surface of the non-weakened region 51 facing the inside of the battery cell 10.
In this embodiment, H 1 ＞H 2 This corresponds to an increase in the stiffness of the weakened region 52, thereby increasing the strength of the weakened region 52 and reducing the risk of the weakened region 52 being damaged under normal use conditions of the battery cell 10.
In some embodiments, H 1 /H 2 ≤5。
H 1 /H 2 May be any one of 1.1, 1.5, 2, 2.5, 3, 3.5, 3.6, 4, 4.5, 5, or a range between any two.
When H is present 1 /H 2 At > 5, excessive hardness of the weak region 52 may result, and there may be a case where the weak region 52 is hardly broken upon thermal runaway of the battery cell 10.
Thus, H 1 /H 2 Less than or equal to 5, the risk that the weak area 52 cannot be damaged in time when the single battery 10 is in thermal runaway is reduced, and the safety of the single battery 10 is improved.
In some embodiments，H 1 /H 2 ≤2.5。
H 1 /H 2 May be any one of 1.1, 1.11, 1.12, 1.2, 1.25, 1.3, 1.4, 1.5, 1.6, 1.7, 1.71, 1.72, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, or a range between any two.
In this embodiment, H 1 /H 2 2.5 below, the risk that the weak area 52 cannot be timely damaged when the battery cell 10 is in thermal runaway can be further reduced.
In some embodiments, 5HBW ≦ H 2 ≤150HBW。
H 2 May be any one of 5HBW, 8HBW, 9HBW, 9.5HBW, 10HBW, 15HBW, 16HBW, 19HBW, 20HBW, 30HBW, 40HBW, 50HBW, 52HBW, 52.5HBW, 53HBW, 60HBW, 70HBW, 80HBW, 90HBW, 100HBW, 110HBW, 120HBW, 130HBW, 140HBW, 150HBW, or a range point value therebetween.
In some embodiments, 5HBW ≦ H 1 ≤200HBW。
H 1 May be any one of 5HBW, 6HBW, 8HBW, 10HBW, 15HBW, 19HBW, 20HBW, 30HBW, 50HBW, 60HBW, 70HBW, 80HBW, 90HBW, 100HBW, 110HBW, 120HBW, 130HBW, 140HBW, 150HBW, 160HBW, 170HBW, 180HBW, 190HBW, 200HBW, or a range between any two of them.
In some embodiments, referring to fig. 7 and 8, fig. 8 is an enlarged view of a portion of a housing part 5 provided in other embodiments of the present application. The minimum thickness of the weak area 52 is A, the minimum thickness of the non-weak area 51 is B, and the following conditions are satisfied: A/B is more than or equal to 0.05 and less than or equal to 0.95.
The minimum thickness of the area of weakness 52 is the thickness at the thinnest point of the area of weakness 52. The minimum thickness of the non-weakened area 51 is the thickness of the thinnest position of the non-weakened area 51.
As shown in fig. 7 and 8, the housing member 5 has a first surface 54 and a second surface 55 which are oppositely arranged, the groove portion 53 is recessed from the first surface 54 toward the second surface 55, and a portion of the housing member 5 between the groove bottom surface 531 and the second surface 55 is the weak area 52.
The first surface 54 and the second surface 55 may be disposed in parallel or at a small angle, for example, if the first surface 54 and the second surface 55 are disposed at a small angle, for example, the angle between the two is within 10 degrees, the minimum distance between the first surface 54 and the second surface 55 is the minimum thickness of the non-weakened area 51; as shown in fig. 7 and 8, if the first surface 54 and the second surface 55 are parallel, the distance between the first surface 54 and the second surface 55 is the minimum thickness of the non-weakened area 51.
The groove bottom surface 531 of the groove portion may be a flat surface or a curved surface. If the groove bottom surface 531 is a plane, the groove bottom surface 531 and the second surface 55 may be parallel or at a small angle. If the groove bottom surface 531 of the groove portion and the second surface 55 are arranged at a small angle, for example, the angle between the groove bottom surface 531 and the second surface 55 is within 10 degrees, the minimum distance between the groove bottom surface 531 of the groove portion and the second surface 55 is the minimum thickness of the weak area 52; as shown in fig. 7, if the groove bottom 531 of the groove portion is parallel to the second surface 55, the distance between the groove bottom 531 and the second surface 55 of the groove portion is the minimum thickness of the weak area 52. As shown in fig. 8, if the groove bottom surface 531 of the groove portion is a curved surface, for example, the groove bottom surface 531 of the groove portion is an arc surface, and the minimum distance between the groove bottom surface 531 of the groove portion and the second surface 55 is the minimum thickness of the weak area 52.
A/B may be any one of 0.05, 0.06, 0.07, 0.08, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.8, 0.85, 0.9, 0.95, or a range between any two.
When a/B < 0.05, the strength of the weak region 52 may be insufficient, and the probability of the weak region 52 breaking under normal use conditions of the battery cell 10 may increase. When a/B is greater than 0.95, the weak region 52 may not be easily damaged when the battery cell 10 is thermally runaway, and the pressure may not be released in time, resulting in an increase in the probability of explosion of the battery cell 10. Therefore, the A/B is more than or equal to 0.05 and less than or equal to 0.95, the probability that the weak area 52 is broken under the normal use condition of the single battery 10 can be reduced, and the probability that the single battery 10 explodes when in thermal runaway can be reduced.
In some embodiments, 0.12 ≦ A/B ≦ 0.8.
A/B may be any one of 0.12, 0.13, 0.14, 0.15, 0.17, 0.2, 0.22, 0.25, 0.27, 0.3, 0.32, 0.35, 0.37, 0.4, 0.42, 0.45, 0.47, 0.5, 0.52, 0.55, 0.57, 0.6, 0.62, 0.65, 0.66, 0.67, 0.7, 0.72, 0.75, 0.77, 0.8, or a range between any two.
In the embodiment, A/B is more than or equal to 0.12 and less than or equal to 0.8, so that the comprehensive performance of the external parts is better, and the weak area 52 is ensured to have enough strength under the normal use condition of the single battery 10 under the condition that the weak area 52 can be timely damaged when the single battery 10 is in thermal runaway. When the groove 53 is formed by pressing, S can be more easily set by controlling a/B to be 0.12 to 0.8 1 /S 2 Less than or equal to 0.5, so as to achieve the purpose of refining the grains in the weak area 52.
In some embodiments, 0.2 ≦ A/B ≦ 0.5.
A/B may be any one of 0.2, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.3, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.4, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.5, or a range between any two.
In this embodiment, the a/B is controlled to be between 0.2 and 0.5, so as to further reduce the risk that the weak region 52 is damaged under the normal use condition of the single battery 10, and ensure that the weak region 52 is damaged in time when the single battery 10 is out of control due to heat, thereby improving the timeliness of pressure relief.
In some embodiments, 0.02mm ≦ A ≦ 1.6mm.
Further, A is more than or equal to 0.06mm and less than or equal to 0.4mm.
In some embodiments, 1mm ≦ B ≦ 5mm.
B may be any one of 1mm, 2mm, 3mm, 4mm, 5mm or a range between any two.
When B > 5mm, the thickness of the non-weakened region 51 is large, the material of the case member 5 is large, the weight of the case member 5 is large, and the economical efficiency is poor. When B <1mm, the thickness of the non-weakened region 51 is small and the deformation resistance of the housing part 5 is poor.
Therefore, B is more than or equal to 1mm and less than or equal to 5mm, so that the shell part 5 has better economical efficiency and better deformation resistance.
Further, B is more than or equal to 1.2mm and less than or equal to 3.5mm.
B may be any one of 1.2mm, 1.25mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3mm, 3.1mm, 3.2mm, 3.3mm, 3.4mm, 3.5mm or a range therebetween.
In the present embodiment, 1.2mm B3.5 mm makes the housing member 5 more economical and resistant to deformation.
Further, B is more than or equal to 2mm and less than or equal to 3mm.
In some embodiments, referring to fig. 9-14, fig. 9 is a schematic structural view of a housing part 5 (illustrating a primary scoring groove 532) according to further embodiments of the present application; fig. 10 is a cross-sectional view E-E of the housing part 5 shown in fig. 9; fig. 11 is a schematic structural view of an enclosure part 5 according to further embodiments of the present application (showing a primary scored groove 532); fig. 12 is a sectional view F-F of the housing part 5 shown in fig. 11; fig. 13 is a schematic view of a construction of a housing part 5 according to further embodiments of the present application (showing a primary indent 532); fig. 14 is a G-G sectional view of the housing member 5 shown in fig. 13. The shell part 5 has a vent section 56, the jacket part 53 comprising a primary scored groove 532, the scored groove 532 being provided along an edge of the vent section 56, the vent section 56 being configured to be openable bordered by the scored groove 532, the weakened area 52 forming a bottom of the scored groove 532.
The relief area 56 is an area where the enclosure part 5 can be opened after the weak area 52 is broken. For example, when the internal pressure of the battery cell 10 reaches a threshold value, the weak region 52 is ruptured, and the pressure relief region 56 is opened outward by the exhaust from the inside of the battery cell 10. In the process, the weakened region 52 splits along the scoring groove 532 and the pressure relief region 56 opens, thereby allowing the pressure relief region 56 to open bounded by the scoring groove 532. After the pressure relief area 56 is opened, the housing member 5 may form a vent at a position corresponding to the pressure relief area 56, and the exhaust inside the battery cell 10 may be discharged through the vent to relieve the pressure inside the battery cell 10.
The scored groove 532 may be formed in the housing part 5 in a variety of ways, such as by stamping, milling, laser etching, etc. The notch groove 532 in the groove portion 53 is only one stage, and the one stage notch groove 532 can be formed by one punching. The scoring groove 532 may be a groove of various shapes, such as an annular groove, an arcuate groove, a U-shaped groove, an H-shaped groove, or the like. The weakened area 52 is formed at the bottom of the score groove 532, and the shape of the weakened area 52 is the same as the score groove 532, for example, the weakened area 52 is a U-shaped groove, and the weakened area 52 extends along a U-shaped track.
As an example, the maximum width of the notching groove 532 is X, X ≦ 10mm. The width of the widest position of the notch groove 532 is the maximum width of the notch groove 532.
In this embodiment, weakened region 52 forms the bottom of score groove 532, and when weakened region 52 is broken, pressure relief area 56 is able to open bounded by weakened region 52 to provide pressure relief, increasing the pressure relief area of enclosure component 5.
In some embodiments, with continued reference to fig. 10, 12 and 14, the housing member 5 has a first surface 54 and a second surface 55 disposed opposite to each other, and the score groove 532 is recessed from the first surface 54 toward the second surface 55.
The first surface 54 may be an inner surface of the housing member 5 facing the interior of the battery cell 10, and the second surface 55 may be an outer surface of the housing member 5 facing away from the interior of the battery cell 10; it is also possible that the first surface 54 is an outer surface of the housing member 5 facing away from the interior of the battery cell 10 and the second surface 55 is an inner surface of the housing member 5 facing towards the interior of the battery cell 10. As an example, the first surface 54 is parallel to the second surface 55, and the minimum thickness of the non-weakened area 51 is the distance between the first surface 54 and the second surface 55.
The groove bottom surface of the engraved groove 532 is the groove bottom surface 531 of the groove portion. The portion of the exterior part 5 between the groove bottom of the score groove 532 and the second surface 55 is the groove bottom wall of the score groove 532, which is the weakened area 52.
In the present embodiment, the groove portion 53 includes only the first-stage scored groove 532, the scored groove 532 is the groove portion 53, and the groove portion 53 is a first-stage groove, which is a simple structure. During molding, the notching groove 532 can be molded on the first surface 54, so that the molding is simple, the production efficiency is improved, and the production cost is reduced.
In some embodiments, referring to fig. 15-20, fig. 15 is a schematic structural view of a housing part 5 according to further embodiments of the present application (showing two-stage scoring grooves 532); fig. 16 is a K-K sectional view of the housing member 5 shown in fig. 15; fig. 17 is a schematic structural view of an outer shell part 5 according to further embodiments of the present application (showing two-stage scored grooves 532); fig. 18 is an M-M sectional view of the housing part 5 shown in fig. 17; fig. 19 is a schematic structural view of an enclosure part 5 according to further embodiments of the present application (showing two-stage scored grooves 532); fig. 20 is an N-N sectional view of the housing member 5 shown in fig. 19. The cover part 5 comprises a first surface 54 and a second surface 55 which are oppositely arranged, the groove part 53 comprises multi-level scored grooves 532, the multi-level scored grooves 532 are sequentially arranged on the cover part 5 along the direction from the first surface 54 to the second surface 55, and the weak area 52 is formed at the bottom of the one-level scored groove 532 which is farthest away from the first surface 54. Wherein the outer jacket member 5 has a pressure relief area 56, each level of the scoring groove 532 being provided along an edge of the pressure relief area 56, the pressure relief area 56 being configured to be openable bordered by the level of the scoring groove 532 furthest from the first surface 54.
The groove portion 53 includes a multi-level scored groove 532, and it will be appreciated that the groove portion 53 is a multi-level groove. Each of the plurality of scoring grooves 532 is disposed along an edge of the vent region 56. It will be appreciated that the plurality of scoring grooves 532 are disposed around the vent region 56 such that the plurality of scoring grooves 532 extend in substantially the same direction and such that the plurality of scoring grooves 532 are substantially the same shape. The score groove 532 in the groove portion 53 may be two, three, four, or more stages. The respective notches 532 may be formed in the outer jacket member 5 by press molding. During the forming, the score grooves 532 may be punched and formed sequentially along the direction from the first surface 54 to the second surface 55. When the multi-stage notching groove 532 is formed in a stamping mode, the multi-stage notching groove 532 can be correspondingly formed through multiple times of stamping, and one-stage notching groove 532 is formed at one time through stamping. The scored groove 532 may be a groove of various shapes, such as an annular groove, an arcuate groove, a U-shaped groove, an H-shaped groove, or the like.
The relief area 56 is an area where the enclosure part 5 can be opened after the area of weakness 52 is broken. The primary score groove 532 furthest from first surface 54 is located at the edge of vent region 56, and during opening of vent region 56, weakened region 52 splits along the primary score groove 532 furthest from first surface 54, thereby allowing vent region 56 to open bounded by the primary score groove 532 furthest from first surface 54.
The weakened region 52 is formed at the bottom of the primary score groove 532 farthest from the first surface 54, and the primary score groove 532 farthest from the first surface 54 is the deepest (innermost) primary score groove 532. Among the adjacent two-stage tracking grooves 532, the one-stage tracking groove 532 distant from the first surface 54 is disposed on the bottom surface of the one-stage tracking groove 532 close to the first surface 54. The portion of the housing part 5 between the groove bottom of the primary scored groove 532 furthest from the first surface 54 and the second surface 55 is the groove bottom wall of the primary scored groove 532 furthest from the first surface 54, i.e. the weakened zone 52. The groove bottom of the primary indent 532 furthest from the first surface 54 is the groove bottom 531 of the groove portion. The first-order score groove 532 farthest from the first surface 54 is the innermost first-order score groove 532b, and the first-order score groove 532 closest to the first surface 54 is the outermost first-order score groove 532a.
As an example, the maximum width of the outermost primary indent 532a is X, X ≦ 10mm. The width of the widest position of the outermost primary scored groove 532a is the maximum width of the outermost primary scored groove 532a.
When the shell part 5 is molded, the multi-stage notching grooves 532 can be molded step by step on the shell part 5, and the molding depth of each stage of notching grooves 532 can be reduced, so that the molding force of the shell part 5 when each stage of notching grooves 532 are molded is reduced, the risk of cracks generated on the shell part 5 is reduced, the shell part 5 is not easy to lose efficacy due to the cracks generated at the position where the notching grooves 532 are arranged, and the service life of the shell part 5 is prolonged.
In some embodiments, referring to fig. 16, 18, and 20, the primary indent 532 furthest from the second surface 55 is recessed from the first surface 54 toward the second surface 55.
Taking the two-stage scoring groove 532 in the groove portion 53 as an example, the two-stage scoring groove 532 is a first-stage scoring groove and a second-stage scoring groove. The first-stage scoring groove is arranged on the first surface 54, namely the first-stage scoring groove is sunken from the first surface 54 to a direction close to the second surface 55, and the second-stage scoring groove is arranged on the bottom surface of the first-stage scoring groove; i.e. the second level of indentations are recessed from the base of the first level of indentations towards the direction close to the second surface 55. The first stage of scored groove is the outermost one of the scored grooves 532a, and the second stage of scored groove is the innermost one of the scored grooves 532b.
The groove part 53 is formed by the multi-stage scored groove 532, and the multi-stage scored groove 532 can be gradually processed from the first surface 54 to the second surface 55 during the forming, so that the forming efficiency is high.
In some embodiments, referring to fig. 21-27, fig. 21 is an isometric view of a housing part 5 provided in some embodiments of the present application; fig. 22 is a schematic structural view of the outer jacket member 5 shown in fig. 21 (showing the primary scored groove 532 and the primary sunken groove 533); fig. 23 is an O-O sectional view of the housing part 5 shown in fig. 22; fig. 24 is a schematic structural view of a housing part 5 according to further embodiments of the present application (showing primary scored grooves 532 and primary sunken grooves 533); fig. 25 is a cross-sectional P-P view of the housing part 5 shown in fig. 24; fig. 26 is a schematic structural view of a housing part 5 according to further embodiments of the present application (showing primary scored grooves 532 and primary sunken grooves 533); fig. 27 is a Q-Q sectional view of the housing member 5 shown in fig. 26. The housing member 5 includes a first surface 54 and a second surface 55 disposed opposite to each other, the groove portion 53 further includes a first-stage sunken groove 533, the sunken groove 533 is recessed from the first surface 54 to a direction close to the second surface 55, and the pressure relief region 56 is formed on a groove bottom wall 5331 of the sunken groove.
Note that, the groove portion 53 may include the one-stage depressed groove 533 regardless of whether the score groove 532 in the groove portion 53 is one-stage or multi-stage. It can be understood that the groove part 53 has both the scored groove 532 and the sunken groove 533, and the groove part 53 is a multi-stage groove. The undercut 533 and the score groove 532 are disposed in a direction from the first surface 54 to the second surface 55. In molding, the sunken groove 533 may be molded on the housing member 5, and then the notch groove 532 may be molded on the groove bottom wall 5331. The undercut 533 may be formed in the housing member 5 by various means, such as punch forming, milling, laser etching, etc.
The bottom wall 5331 of the sunken groove is a portion of the housing member 5 located below the bottom surface of the sunken groove 533, and after the sunken groove 533 is formed on the first surface 54, the remaining portion of the housing member 5 in the region where the sunken groove 533 is located is the bottom wall 5331 of the sunken groove. As shown in fig. 23, 25, and 27, a portion of the housing member 5 located between the groove bottom surface of the sunken groove 533 and the second surface 55 is a groove bottom wall 5331 of the sunken groove. Wherein pressure relief zone 56 can be a portion of the bottom wall 5331 of the sink.
The provision of the undercut 533 reduces the depth of the scored groove 532 while ensuring a constant thickness of the final weakened region 52, thereby reducing the molding force to which the outer jacket member 5 is subjected when molding the scored groove 532, and reducing the risk of cracking the outer jacket member 5. In addition, sink 533 can provide an escape space for pressure relief area 56 during opening, and even if first surface 54 is covered by an obstacle, pressure relief area 56 can still open for pressure relief.
Referring to fig. 28-33, fig. 28 is a schematic structural view of an outer jacket member 5 according to some embodiments of the present disclosure (showing a first-stage scored groove 532 and a second-stage sunken groove 533); fig. 29 is an R-R sectional view of the housing part 5 shown in fig. 28; fig. 30 is a schematic structural view of an enclosure member 5 provided in accordance with still other embodiments of the present application (showing one-stage scored groove 532 and two-stage countersunk groove 533); fig. 31 is an S-S sectional view of the housing member 5 shown in fig. 30; fig. 32 is a schematic structural view of an enclosure component 5 provided in accordance with further embodiments of the present application (showing a one-stage scored groove 532 and a two-stage countersunk groove 533); fig. 33 is a T-T sectional view of the case member 5 shown in fig. 32. The housing member 5 includes a first surface 54 and a second surface 55 disposed opposite to each other, the groove portion 53 further includes a plurality of stages of sunken grooves 533, the plurality of stages of sunken grooves 533 are sequentially disposed on the housing member 5 in a direction from the first surface 54 to the second surface 55, the first stage of sunken groove 533 farthest from the second surface 55 is recessed from the first surface 54 to a position close to the second surface 55, and the pressure relief area 56 is formed on a groove bottom wall 5331 of the first stage of sunken groove farthest from the first surface 54.
Note that, the groove portion 53 may include a multistage depressed groove 533 regardless of whether the scored groove 532 in the groove portion 53 is one stage or multistage. It can be understood that the groove part 53 has both the scored groove 532 and the sunken groove 533, and the groove part 53 is a multi-stage groove. The undercut 533 and the score groove 532 are disposed in a direction from the first surface 54 to the second surface 55. In molding, the multi-stage sunken groove 533 may be molded on the housing part 5, and then the scored groove 532 may be molded on the groove bottom wall 5331 of the one-stage sunken groove farthest from the first surface 54.
The primary sunken groove 533 farthest from the second surface 55 (closest to the first surface 54) is the outermost primary sunken groove 533a, and the primary sunken groove 533 farthest from the first surface 54 is the innermost primary sunken groove 533b. The outermost primary sinker 533a is disposed on the first surface 54, and the outermost primary sinker 533a is recessed from the first surface 54 to be close to the second surface 55.
The bottom wall 5331 of the first-stage sunken groove farthest from the first surface 54 is a portion of the housing member 5 located below the bottom surface of the first-stage sunken groove 533 farthest from the first surface 54, and after the multi-stage sunken grooves 533 are formed in the housing member 5, the remaining portion of the housing member 5 in the region where the first-stage sunken groove 533 farthest from the first surface 54 is the bottom wall 5331 of the sunken groove. As shown in fig. 29, 31, and 33, a portion of the housing member 5 located between the groove bottom and the second surface 55 of the primary sunken groove 533 farthest from the first surface 54 is a groove bottom wall 5331 of the primary sunken groove farthest from the first surface 54. Wherein pressure relief area 56 may be a portion of the bottom wall 5331 of the primary sink furthest from first surface 54.
The sinker 533 in the groove portion 53 may be two-stage, three-stage, four-stage, or more. Among the adjacent two-stage sunken grooves 533, the one-stage sunken groove 533 distant from the first surface 54 is disposed at the bottom surface of the one-stage sunken groove 533 close to the first surface 54. The profile of the groove bottom surface of the multistage depressed groove 533 decreases stepwise in the direction from the first surface 54 to the second surface 55. The respective recessed grooves 533 may be formed in the housing member 5 by various methods, such as punch forming, milling, laser etching, and the like. Taking the example where the sunken grooves 533 of each stage are formed in the housing member 5 by press forming, the sunken grooves 533 of each stage may be formed in sequence along the direction from the first surface 54 to the second surface 55, and then the indented grooves 532 may be formed by press forming. Taking the two-level sinking groove 533 and the one-level indenting groove 532 in the groove 53 as an example, during the stamping, two times of stamping may be performed to form the two-level sinking groove 533 correspondingly, and then one time of stamping may be performed to form the one-level indenting groove 532 correspondingly. As an example, in fig. 28-33, the sunken groove 533 in the groove portion 53 is two-stage.
When the multistage sunken grooves 533 are formed, the forming depth of each stage of sunken groove 533 can be reduced, the forming force applied to the housing part 5 when each stage of sunken groove 533 is formed can be reduced, and the risk of cracking of the housing part 5 can be reduced. Furthermore, multi-stage sink 533 can provide relief space for pressure relief area 56 during opening, and pressure relief area 56 can still open for pressure relief even if first surface 54 is obstructed by an obstacle.
In some embodiments, the inner space of the sinker 533 is a cylinder, prism, frustum, or pyramid.
The inner space of the sinking groove 533 is a space defined by the groove side surface and the groove bottom surface of the sinking groove 533. Wherein, the prism can be triangular prism, quadrangular prism, pentagonal prism, hexagonal prism, etc.; the prism body can be a triangular prism table, a rectangular prism table, a five-prism table or a six-prism table, etc. As an example, in fig. 21 to 33, the inner space of the groove portion 53 is a quadrangular prism, and specifically, the inner space of the groove portion 53 is a rectangular parallelepiped.
In this embodiment, the sunken groove 533 has a simple structure, is easy to form, and can provide more space for the pressure relief area 56 to escape during the opening process.
In some embodiments, referring to fig. 34, fig. 34 is a schematic structural view of an exterior part 5 provided in some embodiments of the present application (illustrating a primary score groove 532, the score groove 532 being V-shaped). Scored groove 532 includes a first groove section 5321 and a second groove section 5322, first groove section 5321 intersecting second groove section 5322, first groove section 5321 and second groove section 5322 being disposed along an edge of pressure relief area 56.
The first and second groove sections 5321 and 5322 can be linear grooves or non-linear grooves, such as circular grooves. In embodiments where the first and second groove sections 5321 and 5322 are linear grooves, it is understood that the first and second groove sections 5321 and 5322 each extend along a straight line, and that the first and second groove sections 5321 and 5322 may be disposed at an acute, right, or obtuse angle. First groove section 5321 and second groove section 5322 can be arranged in a crossing manner, for example, the crossing position of first groove section 5321 and second groove section 5322 is located at the midpoint position of first groove section 5321 and the midpoint position of second groove section 5322; as shown in fig. 34, the intersection of first groove section 5321 and second groove section 5322 may be located at one end of first groove section 5321 and one end of second groove section 5322, first groove section 5321 and second groove section 5322 may form a V-shaped structure, and scored groove 532 may be V-shaped.
In this embodiment, the stress is more concentrated at the intersection of first groove section 5321 and second groove section 5322, so that the region of weakness 52 can be broken first at the location where first groove section 5321 intersects second groove section 5322. In the case where the initiation pressure of the battery cell 10 is constant, the weak region 52 may be made thicker, reducing the formation depth of the score groove 532.
In some embodiments, referring to fig. 9, 15, 22, and 28, score groove 532 can further include a third groove segment 5323, first groove segment 5321 and third groove segment 5323 being disposed opposite one another, second groove segment 5322 intersecting third groove segment 5323, first groove segment 5321, second groove segment 5322, and third groove segment 5323 being disposed along an edge of pressure relief region 56.
The first, second and third groove sections 5321, 5322, 5323 can each be linear grooves or non-linear grooves, such as circular grooves. In embodiments where the first groove section 5321, the second groove section 5322 and the third groove section 5323 are all linear grooves, it can be appreciated that the first groove section 5321, the second groove section 5322 and the third groove section 5323 all extend along a straight line, and the first groove section 5321 and the third groove section 5323 can be arranged in parallel or at an angle. Both the first groove section 5321 and the third groove section 5323 can be perpendicular to the second groove section 5322, or they can be non-perpendicular to the second groove section 5322.
The connection position of the second groove section 5322 and the first groove section 5321 may be located at one end of the first groove section 5321, or may be located at a position offset from one end of the first groove section 5321, for example, the connection position of the second groove section 5322 and the first groove section 5321 is located at the midpoint position of the first groove section 5321 in the extending direction; the connection position of the second groove section 5322 and the third groove section 5323 may be located at one end of the third groove section 5323, or may be located at a position offset from one end of the third groove section 5323, for example, the connection position of the second groove section 5322 and the third groove section 5323 is located at a midpoint position of the third groove section 5323 in the extending direction.
It should be noted that in the embodiment where the groove portion 53 includes multiple levels of the scored groove 532, it can be understood that, in the adjacent two levels of the scored grooves 532, the first groove section 5321 of the one level of the scored groove 532 far from the first surface 54 is disposed on the groove bottom surface of the first groove section 5321 of the one level of the scored groove 532 near the first surface 54; the second groove section 5322 of the primary scored groove 532 remote from the first surface 54 is disposed at the groove bottom of the second groove section 5322 of the primary scored groove 532 adjacent to the first surface 54; a third groove section 5323 of the primary indent 532 distal to the first surface 54 is disposed at the groove bottom of the third groove section 5323 of the primary indent 532 proximal to the first surface 54.
In this embodiment, the pressure relief region 56 can be opened with the first groove section 5321, the second groove section 5322, and the third groove section 5323 as boundaries, and when the battery cell 10 is relieved of pressure, the pressure relief region 56 is opened more easily, thereby achieving large-area pressure relief of the housing member 5.
In some embodiments, with continued reference to fig. 9, 15, 22, and 28, first groove section 5321, second groove section 5322, and third groove section 5323 define two pressure relief zones 56, one on each side of second groove section 5322.
As an example, first, second, and third channel segments 5321, 5322, 5323 form an H-shaped scored groove 532, with the connection of second channel segment 5322 to first channel segment 5321 being at a midpoint of first channel segment 5321, and the connection of third channel segment 5323 to second channel segment 5322 being at a midpoint of third channel segment 5323. Two pressure relief zones 56 are symmetrically disposed on either side of the second trough section 5322, it being understood that the areas of the two pressure relief zones 56 are equal. In other embodiments, two pressure relief zones 56 can be asymmetrically disposed on either side of second slot segment 5322 such that the areas of two pressure relief zones 56 are unequal, e.g., first slot segment 5321 and third slot segment 5323 are perpendicular to second slot segment 5322, the connection location of second slot segment 5322 to first slot segment 5321 is offset from the midpoint location of first slot segment 5321, and/or the connection location of third slot segment 5323 to second slot segment 5322 is at the midpoint location of third slot segment 5323.
The two pressure relief areas 56 are respectively located on both sides of the second section 5322, so that the two pressure relief areas 56 are demarcated by the second section 5322, and after the housing member 5 is broken at the location of the second section 5322, the two pressure relief areas 56 can be opened in a split manner along the first section 5321 and the third section 5323 to achieve pressure relief, which can effectively improve the pressure relief efficiency of the housing member 5.
In other embodiments, first groove section 5321, second groove section 5322, and third groove section 5323 are connected in series, first groove section 5321, second groove section 5322, and third groove section 5323 defining a pressure relief region 56.
First groove section 5321, second groove section 5322, and third groove section 5323, connected in series, can form U-shaped scored groove 532.
In some embodiments, the score groove 532 is a groove that extends along a non-closed trajectory.
The non-closed locus refers to a locus with two ends in the extending direction being not connected, and the non-closed locus can be an arc-shaped locus, a U-shaped locus and the like.
In this embodiment, the scored groove 532 is a groove along a non-closed path, and the pressure relief area 56 may be opened in a flip-over manner, and the pressure relief area 56 is eventually connected to other areas of the outer shell member 5 after being opened, thereby reducing the risk of splashing after the pressure relief area 56 is opened.
In some embodiments, referring to fig. 11, 17, 24 and 30, the scoring groove 532 is a circular arc groove.
The arc-shaped groove is a groove extending along an arc-shaped track, and the arc-shaped track is a non-closed track. The central angle of the circular arc groove may be less than, equal to, or greater than 180 °.
The arc-shaped groove has simple structure and is easy to form. During venting, venting zone 56 can snap along the arcuate slot to allow venting zone 56 to snap open.
In some embodiments, referring to fig. 13, 19, 26 and 32, the score groove 532 is a groove that extends along a closed trajectory.
The closed track refers to a track with two ends connected end to end, and the closed track can be a circular track, a rectangular track and the like.
During the pressure relief process, the case member 5 can be ruptured along the scored groove 532, so that the pressure relief area 56 can be opened in a breakaway manner, increasing the pressure relief area of the case member 5 and increasing the rate of pressure relief of the case member 5.
In some embodiments, the score groove 532 is an annular groove.
The annular groove can be a rectangular annular groove or a circular annular groove.
The annular groove is simple in construction and easy to form, and the housing part 5 can be broken rapidly along the annular groove during the pressure relief process to allow the pressure relief area 56 to be opened rapidly.
In some embodiments, the relief zone 56 has an area D that satisfies: 90mm 2 ≤D≤1500mm 2 。
In fig. 9, 11, 13, 15, 17, 19, 22, 24, 26, 28, 30, 32, and 34, the area of the shaded portion is the area of the pressure relief region 56.
It should be noted that in the embodiment including multiple levels of scoring groove 532 in trough portion 53, the area of pressure relief area 56 is the area defined by the deepest (innermost) level of scoring groove 532.
D may be 90mm 2 、95mm 2 、100mm 2 、150mm 2 、200mm 2 、250mm 2 、300mm 2 、350mm 2 、400mm 2 、450mm 2 、500mm 2 、550mm 2 、600mm 2 、650mm 2 、700mm 2 、750mm 2 、800mm 2 、900mm 2 、950mm 2 、1000mm 2 、1050mm 2 、1100mm 2 、1150mm 2 、1200mm 2 、1250mm 2 、1300mm 2 、1350mm 2 、1400mm 2 、1450mm 2 、1500mm 2 Any one point value or a range value between any two.
When D is less than 90mm 2 In the process, the pressure relief area of the shell part 5 is small, and the pressure relief timeliness is poor when the battery monomer 10 is out of control due to heat; d is more than 1500mm 2 The vent region 56 has poor impact resistance, deformation of the vent region 56 increases after a force is applied, and the weak region 52 is easily deformed under normal use conditions of the battery cell 10Damage, affecting the life of the cell 10. Therefore, 90mm 2 ≤D≤1500mm 2 The service life of the single battery 10 can be prolonged, and the safety of the single battery 10 can be improved.
Further, 150mm 2 ≤D≤1200mm 2 . The comprehensive performance of the housing part 5 is better, and the housing part 5 has a larger pressure relief area and better impact resistance.
Further, 200mm 2 ≤D≤1000mm 2 。
Further, 250mm 2 ≤D≤800mm 2 。
In some embodiments, referring to fig. 4-34, the housing member 5 has a first surface 54 and a second surface 55 opposite to each other, the groove portion 53 is recessed from the first surface 54 toward the second surface 55, the groove portion 53 forms an outer edge 534 on the first surface 54, and the non-weakened area 51 is a region of the housing member 5 beyond a predetermined distance from the outer edge 534. Wherein the preset distance is L.
L may be 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, etc.
In the embodiment shown in fig. 9-14, the trough portion 53 includes only one level of scored groove 532, the scored groove 532 is disposed on the first surface 54, the intersection of the groove side of the scored groove 532 with the first surface 54 forms an outer edge 534, and the groove side of the scored groove 532 is disposed around the groove bottom of the scored groove 532. It is noted that in the embodiment shown in fig. 13, since the scored groove 532 is a groove extending along a closed trajectory, the intersection of the groove side of the scored groove 532 with the first surface 54 forms an inner circular line and an outer circular line outside the inner circular line, the outer circular line being the outer edge 534.
In the embodiment shown in fig. 15-20, the groove portion 53 includes only multi-level scoring grooves 532, the outermost one-level scoring grooves 532a are disposed on the first surface 54, and the groove sides of the outermost one-level scoring grooves 532a intersect the first surface 54 to form outer edges 534. It should be noted that in the embodiment shown in fig. 19, since the scored groove 532 is a groove extending along a closed track, the outermost one-stage scored groove 532a intersects the first surface 54 to form an inner circular line and an outer circular line outside the inner circular line, and the outer circular line is the outer edge 534.
In the embodiment shown in fig. 21-27, slot portion 53 further includes a primary sunken slot 533, sunken slot 533 is disposed on first surface 54, a slot side of sunken slot 533 intersects first surface 54 to form outer edge 534, and a slot side of sunken slot 533 is disposed around a slot bottom of sunken slot 533. In the embodiment shown in fig. 28-33, the groove portion 53 further includes a plurality of stages of sunken grooves 533, the outermost one-stage sunken groove 533a is disposed to intersect the first surface 54, and the groove side surface of the outermost one-stage sunken groove 533a intersects the first surface 54 to form an outer edge 534.
It will be appreciated that the distance between the outer edge 534 and the inner edge 511 of the non-weakened area 51 is a predetermined distance L, and the shape of the inner edge 511 of the non-weakened area 51 may be substantially the same as the shape of the outer edge 534. The preset distance L may be in a direction perpendicular to the thickness direction of the non-weak area 51, that is, the preset distance L may be measured in a direction perpendicular to the thickness direction of the non-weak area 51. In measuring the average grain size of the non-weakened region 51, the measurement may be made at a region other than the distance from the outer edge 534.
In the present embodiment, the region of the housing member 5 other than the predetermined distance from the outer edge 534 is the non-weakened region 51, the non-weakened region 51 is at a distance from the groove portion 53, and the non-weakened region 51 is not easily affected by the process of forming the groove portion 53, so that the crystal grains of the non-weakened region 51 are more uniform.
In some embodiments, L =5mm.
Note that, as shown in fig. 9 and 15, in an embodiment in which the first groove section 5321 and the third groove section 5323 of the score groove 532 are disposed opposite to each other, taking the example of the first groove section 5321 and the third groove section 5323 being parallel, when the distance between the first groove section 5321 and the third groove section 5323 is greater than 2 × l, the inner edge 511 of the non-weak region 51 is locally located at the pressure relief region 56, so that the pressure relief region 56 is partially located at the non-weak region 51. In another embodiment, referring to fig. 35, fig. 35 is a schematic structural view of the outer jacket component 5 according to another embodiment of the present application, when the distance between the first groove section 5321 and the third groove section 5323 is less than or equal to 2 × l, the inner edge 511 of the non-weakened area 51 is not located in the pressure relief area 56, and the inner edge 511 of the non-weakened area 51 is substantially rectangular. The first groove section 5321 has a distance L from the inner edge 511 of the non-weakened area 51 in the width direction of the first groove section 5321; the first groove section 5321 has a spacing L from the inner edge 511 of the non-weakened area 51 along the length direction of the first groove section 5321; the third groove section 5323 has a distance L from the inner edge 511 of the non-weakened area 51 in the width direction of the third groove section 5323; the third groove section 5323 is spaced apart from the inner edge 511 of the non-weakened area 51 by L along the length of the third groove section 5323.
In some embodiments, referring to fig. 36, fig. 36 is a die view (schematic view) of a housing part 5 according to other embodiments of the present application. The shell part 5 further comprises a transition region 57, the transition region 57 connecting the weakened region 52 and the non-weakened region 51, the transition region 57 having an average grain size S 3 And satisfies the following conditions: s 3 ≤S 2 。
As an example, S 3 ＞S 1 。
The transition region 57 is a portion of the exterior member 5 connecting the weakened region 52 and the non-weakened region 51, the transition region 57 is provided around the outside of the weakened region 52, the non-weakened region 51 is provided around the outside of the transition region 57, and the weakened region 52, the transition region 57 and the non-weakened region 51 are integrally formed.
The average grain size of the transition region 57 may gradually decrease from the non-weakened region 51 to the weakened region 52. As an example, as shown in fig. 36, taking the case where the groove portions 53 include the primary sunken grooves 533 and the primary indented grooves 532 as an example, the average grain size of the transition region 57 at the outer side regions of the sunken grooves 533 may be larger than the average grain size of the transition region 57 at the bottom regions of the sunken grooves 533, and the average grain size of the transition region 57 at the outer side regions of the sunken grooves 533 may be smaller than or equal to the average grain size S of the non-weakened regions 51 2 The average grain size of the transition region 57 at the bottom region of the sinker 533 may be larger than the average grain size S of the weakened region 52 1 。
In this embodiment, the transition region 57 functions to connect the weakened region 52 and the non-weakened region 51, and the weakened region 52 and the non-weakened region 51 are integrally formed.
In some embodiments, referring to fig. 37, fig. 37 is a schematic structural view of an end cap 11 according to some embodiments of the present disclosure. The housing member 5 is an end cap 11, the end cap 11 being for closing an opening of a case 12, the case 12 being for accommodating the electrode assembly 2.
It will be appreciated that the end cap 11 is provided with a channel portion 53 to form the weakened area 52 and the non-weakened area 51, respectively. The first surface 54 and the second surface 55 of the housing member 5 are two surfaces of the end cap 11 opposite in the thickness direction, respectively, i.e., one of the first surface 54 and the second surface 55 is an inner surface of the end cap 11 in the thickness direction, and the other is an outer surface of the end cap 11 in the thickness direction.
The end cap 11 may be a circular, rectangular plate-like structure.
By way of example, in the embodiment shown in fig. 37, the end cap 11 is a rectangular plate-like structure.
In this embodiment, the end cap 11 has a pressure relief function, so as to ensure the safety of the battery cell 10.
In some embodiments, referring to fig. 38 and 39, fig. 38 is a schematic structural view of the housing 12 according to some embodiments of the present disclosure; fig. 39 is a schematic structural diagram of the housing 12 according to another embodiment of the present application. The case member 5 is a case 12, the case 12 having an opening, the case 12 accommodating the electrode assembly 2.
In the present embodiment, the housing 12 of the housing 1 is the housing part 5, and the end cap 11 of the housing 1 is used for closing the opening of the housing 12. The housing 12 may be a hollow structure with an opening formed at one end, or may be a hollow structure with openings formed at the opposite ends. The housing 12 may be a rectangular parallelepiped, a cylinder, or the like.
In the present embodiment, the housing member 5 is a casing 12, so that the casing 12 has a pressure relief function, and the safety of the battery cell 10 is ensured.
In some embodiments, the housing 12 includes a plurality of wall portions 121 integrally formed, the plurality of wall portions 121 collectively defining an interior space of the housing 12, at least one wall portion 121 being provided with the groove portion 53.
In the case 12, a groove portion 53 may be provided on one wall portion 121 to form the weakened area 52 and the non-weakened area 51 integrally formed on the wall portion 121; it is also possible to provide the groove portions 53 on the plurality of wall portions 121 to form the weakened area 52 and the non-weakened area 51 integrally formed on each wall portion 121 where the groove portions 53 are provided. As for the wall portions 121 provided with the groove portions 53, the first surface 54 and the second surface 55 of the case member 5 are two surfaces of the wall portion 121 opposing in the thickness direction, respectively, i.e., one of the first surface 54 and the second surface 55 is an inner surface of the wall portion 121 in the thickness direction, and the other is an outer surface of the wall portion 121 in the thickness direction.
In the present embodiment, the plurality of wall portions 121 are integrally molded, so that the wall portions 121 provided with the groove portions 53 have better reliability.
In some embodiments, with continued reference to fig. 38 and 39, the plurality of wall portions 121 include a bottom wall 121b and a plurality of side walls 121a surrounding the bottom wall 121b, and the housing 12 is open at an end opposite to the bottom wall 121b. The bottom wall 121b is provided with a groove portion 53; and/or at least one side wall 121a is provided with a groove 53.
In the present embodiment, the housing 12 is a hollow structure with an opening formed at one end. The side walls 121a in the housing 12 may be three, four, five, six, or more. One, two, three, four, five, six, or more sidewalls 121a may be provided with the groove portion 53.
As an example, in fig. 38, only one side wall 121a is provided with a groove portion 53 to form a weakened area 52 and a non-weakened area 51 on the side wall 121a correspondingly; in fig. 39, only the bottom wall 121b is provided with the groove portion 53 to form the weakened area 52 and the non-weakened area 51 on the bottom wall 121b correspondingly.
In some embodiments, with continued reference to fig. 38 and 39, the housing 12 is a cuboid.
It will be appreciated that there are four side walls 121a in the housing 12.
The cuboid shell is suitable for a square battery monomer, and can meet the high-capacity requirement of the battery monomer 10.
In some embodiments, the material of the housing member 5 includes an aluminum alloy.
The aluminum alloy housing member 5 is light in weight, has excellent ductility, has excellent plastic deformability, and is easy to mold.
S is more than or equal to 0.1 1 /S 2 In the example of 0.5 or less, since the aluminum alloy has good ductility, the aluminum alloy can be formed by pressingWhen the groove 53 is formed in the housing member 5, it is easier to form S 1 /S 2 The molding quality is higher by controlling the content of the resin to be less than 0.5 (including 0.5).
In some embodiments, the aluminum alloy comprises the following components in percentage by mass: more than or equal to 99.6 percent of aluminum, less than or equal to 0.05 percent of copper, less than or equal to 0.35 percent of iron, less than or equal to 0.03 percent of magnesium, less than or equal to 0.03 percent of manganese, less than or equal to 0.25 percent of silicon, less than or equal to 0.03 percent of titanium, less than or equal to 0.05 percent of vanadium, less than or equal to 0.05 percent of zinc and less than or equal to 0.03 percent of other single elements. The aluminum alloy has lower hardness and better forming capability, reduces the forming difficulty of the groove part 53, improves the forming precision of the groove part 53, and improves the pressure relief consistency of the shell part 5.
In some embodiments, the aluminum alloy comprises the following components in percentage by mass: more than or equal to 96.7 percent of aluminum, more than or equal to 0.05 percent and less than or equal to 0.2 percent of copper, less than or equal to 0.7 percent of iron, less than or equal to 1.5 percent of manganese, less than or equal to 0.6 percent of silicon, less than or equal to 0.1 percent of zinc, less than or equal to 0.05 percent of other single element components, and less than or equal to 0.15 percent of other total element components. The housing member 5 made of such an aluminum alloy has a higher hardness, a high strength, and a good resistance to breakage.
The embodiment of the present application provides a battery cell 10 including the outer jacket member 5 provided in any one of the above embodiments.
In some embodiments, the battery cell 10 further includes a case 12, the case 12 having an opening, the case 12 for housing the electrode assembly 2. The housing part 5 is an end cap 11, the end cap 11 closing the opening.
In some embodiments, the housing member 5 is a case 12, the case 12 having an opening, the case 12 for housing the electrode assembly 2. The battery cell 10 further includes an end cap 11, the end cap 11 closing the opening.
The embodiment of the present application provides a battery 100, which includes the single battery 10 provided in any one of the above embodiments.
In some embodiments, referring to fig. 40, fig. 40 is a schematic structural view of a battery cell 10 according to some embodiments of the present disclosure, and a weak area 52 is located at a lower portion of the battery cell 10.
In the battery cell 10, along the height direction of the housing 1 of the battery cell 10, the portion of the battery cell 10 below the midplane Y of the housing 1, which is perpendicular to the height direction of the housing 1, is the lower portion of the battery cell 10, and the distances from the midplane Y to the two end faces of the housing 1 in the height direction are equal. For example, the housing 1 includes a case 12 and an end cap 11, and the end cap 11 closes an opening of the case 12. The housing 12 and the end cap 11 are arranged along the height direction of the housing 1, and along the height direction of the housing 1, the middle plane Y is located at a middle position between the outer surface of the end cap 11 facing away from the housing 12 and the outer surface of the housing 12 facing away from the end cap 11.
The weak area 52 is located at the lower portion of the battery cell 10, and the groove portion 53 is located at the lower portion of the battery cell 10, and both the weak area 52 and the groove portion 53 are located below the middle plane Y. The area of weakness 52 may be located in the housing 12 and the area of weakness 52 may also be located in the end cap 11. The weakened area 52 may be located in the side wall 121a of the housing 12 or in the bottom wall 121b of the housing 12. As shown in fig. 40, taking the case where the weakened area 52 is located on the side wall 121a of the housing 12, it may be that the bottom wall 121b of the housing 12 is located below the end cap 11, and the weakened area 52 is located below the midplane Y, so that the distance from the weakened area 52 to the bottom wall 121b of the housing 12 is greater than the distance from the weakened area 52 to the end cap 11.
Because the weak area 52 is located at the lower part of the single battery 10, in the use process of the battery 100, the weak area 52 can receive a larger acting force under the action of the gravity of the electrode assembly 2, the electrolyte and the like in the single battery 10, and because the weak area 52 and the non-weak area 51 are of an integrated structure, the battery has good structural strength and better reliability, and the service life of the single battery 10 is prolonged.
In some embodiments, the battery cell 10 includes a case 12, the case 12 is configured to accommodate the electrode assembly 2, the case 12 includes a bottom wall 121b integrally formed and a plurality of side walls 121a surrounding the bottom wall 121b, the bottom wall 121b is integrally formed with the side walls 121a, the case 12 is open at an end opposite to the bottom wall 121b, and the weak area 52 is located at the bottom wall 121b.
Understandably, the bottom wall 121b is located below the midplane Y.
In the present embodiment, the weakened region 52 is located on the bottom wall 121b, so that the weakened region 52 is arranged downward, and when the battery cell 10 is thermally runaway and the weakened region 52 is damaged, the emission in the battery cell 10 is ejected downward, so that the risk of safety accidents is reduced. For example, in the vehicle 1000, the battery 100 is generally installed below the passenger compartment, and the weak area 52 is disposed downward, so that the emissions discharged by the thermal runaway of the battery cell 10 are ejected in a direction away from the passenger compartment, the influence of the emissions on the passenger compartment is reduced, and the risk of safety accidents is reduced.
In some embodiments, cell 10 includes end cap 11, end cap 11 configured to close an opening of case 12, case 12 configured to receive electrode assembly 2, and weakened area 52 located at end cap 11.
It will be appreciated that the end cap 11 is located below the midplane Y.
In the embodiment, the weak area 52 is located on the end cover 11, so that the weak area 52 is arranged downwards, and when the battery cell 10 is in thermal runaway and the weak area 52 is damaged, the emissions in the battery cell 10 are sprayed downwards, so that the risk of safety accidents is reduced.
The embodiment of the present application provides an electric device, including the battery 100 provided in any one of the above embodiments.
In some embodiments, the present embodiments provide an end cap 11 for a battery cell 10, where the end cap 11 includes a non-weakened area 51 and a weakened area 52 that are integrally formed. The end cap 11 is provided with a groove portion 53, a non-weak area 51 is formed around the groove portion 53, a weak area 52 is formed at the bottom of the groove portion 53, and the weak area 52 is configured to be broken when the battery cell 10 is discharged of internal pressure. The end cap 11 has a first surface 54 facing away from the interior of the battery cell 10, the groove portion 53 forms an outer edge 534 at the first surface 54, and the area of the end cap 11 outside of a predetermined distance from the outer edge 534 is a non-weakened area 51, the predetermined distance being L, L =5mm. The average grain size of the weakened region 52 is S 1 The average grain size of the non-weakened region 51 is S 2 The minimum thickness of the weakened region 52 is A, the minimum thickness of the non-weakened region 51 is B, and the hardness of the weakened region 52 is H 1 The non-weakened region 51 has a hardness of H 2 And satisfies the following conditions: s is more than or equal to 0.1 1 /S 2 ≤0.5，5≤A/S 1 ≤20，190HBW/mm≤H 1 /A≤4000HBW/mm，1＜H 1 /H 2 ≤2.5，0.2≤A/B≤0.5。
In some embodiments, the present application provides a housing 12 for a battery cell 10The housing 12 includes integrally formed non-weakened areas 51 and weakened areas 52. The case 12 is provided with a groove portion 53, the non-weak region 51 is formed around the groove portion 53, the weak region 52 is formed at the bottom of the groove portion 53, and the weak region 52 is configured to be broken when the battery cell 10 is discharged of the internal pressure. The housing 12 has a first surface 54 facing away from the interior of the battery cell 10, the groove portion 53 forms an outer edge 534 at the first surface 54, and the region of the housing 12 outside of a predetermined distance from the outer edge 534 is a non-weakened region 51, the predetermined distance being L, L =5mm. The average grain size of the weakened region 52 is S 1 The average grain size of the non-weakened region 51 is S 2 The minimum thickness of the weakened area 52 is A, the minimum thickness of the non-weakened area 51 is B, and the hardness of the weakened area 52 is H 1 The non-weakened region 51 has a hardness of H 2 And satisfies the following conditions: s is more than or equal to 0.1 1 /S 2 ≤0.5，5≤A/S 1 ≤20，190HBW/mm≤H 1 /A≤4000HBW/mm，1＜H 1 /H 2 ≤2.5，0.2≤A/B≤0.5。
The features and properties of the present application are described in further detail below with reference to examples.
In each of the examples and comparative examples, the battery cell 10 was a prismatic battery cell, the end cap 11 in the battery cell 10 was used as the exterior member 5, the capacity of the battery cell 10 was 150Ah, and the chemical system was NCM.
1. Test method
(1) Average grain size of the weakened area 52 and the non-weakened area 51.
The average grain size test of the weak areas 52 and the non-weak areas 51 employs an Electron Back Scattering Diffraction (EBSD) method. The casing member 5 is cut into 3 sections, each having a weakened region 52 and a non-weakened region 51 in cross-section at both ends of the middle section. The cutting direction is perpendicular to the length of the weakened area 52 and the cutting equipment does not change the grain structure. Selecting the middle section for sampling, then electropolishing the sample, fixing the sample on a sample table inclined at 70 degrees, selecting a proper magnification, performing Electron Back Scattering Diffraction (EBSD) scanning by using a Scanning Electron Microscope (SEM) provided with an EBSD accessory, and finally calculating the average grain size (namely the diameter of an isovolumetric circle of complete grains in the inspection surface) according to the scanning result.
(2) Minimum thickness test of the weakened area 52 and the non-weakened area 51.
The housing member 5 was cut into 3 pieces, and the middle piece was used as a sample, and both ends of the sample had a weakened area 52 and a non-weakened area 51 in cross section. The cutting direction is perpendicular to the length of the weakened area 52. After the section of the middle section is polished to remove burrs sufficiently, the sample is placed in a three-dimensional coordinate measuring instrument, and the thickness of the weak area 52 and the non-weak area 51 on the section is measured.
(3) The zones of weakness 52 and the zones of non-weakness 51 are tested for hardness.
The housing member 5 was cut into 3 pieces, and the middle piece was used as a sample, and both ends of the sample had a weakened area 52 and a non-weakened area 51 in cross section. The cutting direction is perpendicular to the length direction of the weak area 52, and after the test section is polished to remove burrs sufficiently, the sample is horizontally placed (the section direction of the sample is parallel to the extrusion direction of the hardness measuring instrument) on a Brinell hardness measuring instrument for hardness measurement. If the width of the weak area 52 is less than 1mm or the indenter size of the Brinell hardness tester is much larger than the width of the weak area 52, a non-standard indenter is processed to measure the hardness according to the Brinell hardness measurement and conversion principle.
(4) The rate of cracking of the weakened area 52 under normal use conditions of the battery cell 10.
The battery cell 10 was placed at 25. + -. 2 ℃ and subjected to cyclic charge/discharge with a charge/discharge interval of 5% to 97% SOC, while monitoring the gas pressure generated inside the battery cell 10 and performing 500 tests. The test cut-off conditions were: the battery cell 10 life is decreased to 80% soh or the weak region 52 is ruptured during the cycle of any one group of the battery cells 10. The conditions for determining the cracking of the weak area 52 are as follows: the internal gas pressure of the battery cell 10 is decreased by > 10% of the maximum atmospheric pressure. The crack rate of the weakened region 52 was counted, crack rate = number of cracks/total number 100%.
(5) The explosion rate of the battery cell 10 at thermal runaway.
A small heating film is arranged in the single battery 10, the heating film is electrified to heat the single battery 10 until the single battery 10 is out of control due to heat, and whether the single battery 10 explodes or not is observed. The 500-set test was repeated and the explosion rate of the battery cell 10 was counted, the explosion rate = 100% of the number/total number of explosions.
2. Test results
In each of the examples and comparative examples, the average grain size S of the weak region 52 1 Average grain size S of non-weakened area 51 2 Minimum thickness A of the weakened area 52, minimum thickness B of the non-weakened area 51, hardness H of the weakened area 52 1 Hardness H of non-weakened region 51 2 The test results of (A) are shown in Table I, in which S 1 And S 2 In mm, A and B in mm, H 1 And H 2 Unit of (d) is HBW; the rate of rupture Q of the weakened area 52 under normal use conditions of the battery cell 10 1 And the explosion rate Q of the battery cell 10 at the time of thermal runaway 2 As shown in table two.
Watch 1
Figure BDA0003948632630000181
Figure BDA0003948632630000191
Figure BDA0003948632630000201
Watch two
Figure BDA0003948632630000202
Figure BDA0003948632630000211
From examples 1 to 7, it can be seen from the combination of Table I and Table II that 1 /S 2 Less than or equal to 0.9, the weak area 52 has a lower rate of cracking under normal use conditions of the battery cell 10. In comparative example 1, 0.9 < S 1 /S 2 <1, the weak region 52 is in the cellThe cracking rate of the monomer 10 is obviously increased under the normal use condition; in comparative example 2, S 1 /S 2 =1, the rate of rupture of the weakened area 52 under normal use conditions of the battery cell 10 is significantly increased; in comparative example 3, S 1 /S 2 The rate of cracking of the weakened region 52 under normal cell 10 use conditions is also significantly increased > 1. Comparing examples 1 to 7 with comparative examples 1 to 3, it can be seen that S is 1 /S 2 The control is not more than 0.9, the risk that the weak area 52 is damaged under the normal use condition of the battery single body 10 can be effectively reduced, and therefore the service life of the battery single body 10 is prolonged.
According to example 7, when S is 1 /S 2 When the voltage is less than 0.05, the difficulty that the weak area 52 is damaged when the single battery 10 is out of control due to heat is increased, the pressure is not released in time, and the risk that the single battery 10 explodes is obviously increased. As can be seen from examples 3 to 5, when S is 0.1. Ltoreq.S 1 /S 2 And when the cracking rate of the weak area 52 under the normal use condition of the single battery 10 and the explosion rate of the single battery 10 under the thermal runaway are lower than or equal to 0.5, the weak area 52 is ensured to have enough strength under the normal use condition of the single battery 10 under the condition that the weak area 52 can be timely damaged under the thermal runaway of the single battery 10.
As can be seen from a comparison of examples 9 to 12 with example 8, when 1. Ltoreq. A/S 1 When the explosion rate is less than or equal to 100, the single battery 10 can timely release pressure when thermal runaway occurs, and the explosion rate of the single battery 10 is low. When A/S is more than or equal to 5 1 When the thermal runaway temperature is less than or equal to 20, the comprehensive performance of the single battery 10 is better, and the cracking rate of the weak area 52 under the normal use condition of the single battery 10 and the explosion rate of the single battery 10 under the thermal runaway are lower.
As can be seen from a comparison of examples 14 to 17 with example 13, when H is 1 When the/A is more than 10000HBW/mm, the cracking rate of the weak area 52 under the normal use condition of the battery cell 10 is higher, and the comparison between examples 14 to 17 and example 18 shows that when H is 1 When the/A is less than 5HBW/mm, the explosion rate of the battery cell 10 is high when the thermal runaway occurs. And H is more than or equal to 5HBW/mm 1 the/A is less than or equal to 10000HBW/mm, the risk of the weak area 52 breaking under the normal use condition of the single battery 10 can be reduced, and the weak area 52 can be used for timely preventing the single battery 10 from thermal runawayAnd the pressure is relieved, so that the explosion risk of the battery cell 10 is reduced. From examples 15 to 16, it can be seen that when 190 HBW/mm.ltoreq.H 1 When the/A is less than or equal to 4000HBW/mm, the comprehensive performance of the single battery 10 is better, and the cracking rate of the weak area 52 under the normal use condition of the single battery 10 and the explosion rate of the single battery 10 under thermal runaway are lower.
As can be seen from a comparison of examples 19 to 21 with examples 22 to 23, when H 1 /H 2 When the thickness is less than or equal to 1, the cracking rate of the weak area 52 under the normal use condition of the single battery 10 is higher. And H 1 /H 2 Greater than 1 is effective in reducing the rate of cracking of the weakened region 52 under normal use conditions of the cell 10. When examples 20 to 21 and example 19 are compared, it is found that H 1 /H 2 At > 5, the explosion rate of the battery cell 10 at thermal runaway is high. And H 1 /H 2 The risk of explosion of the battery cell 10 can be reduced by less than or equal to 5.
It can be seen from comparison of examples 25 to 30 with example 24 that the explosion rate of the battery cell 10 at thermal runaway is higher when A/B > 0.95. Comparing examples 25 to 30 and example 31, it can be seen that when a/B < 0.05, the weak region 52 has a high cracking rate under normal use conditions of the battery cell 10. And A/B is more than or equal to 0.05 and less than or equal to 0.95, so that the risk of the rupture of the weak area 52 under the normal use condition of the single battery 10 can be reduced, and the pressure can be timely relieved through the weak area 52 when the single battery 10 is out of control due to heat, so that the risk of the explosion of the single battery 10 is reduced. It can be seen from examples 26 to 29 that when a/B is 0.12 or more and 0.8 or less, the overall performance of the battery cell 10 is better, the cracking rate of the weak region 52 under the normal use condition of the battery cell 10 and the explosion rate of the battery cell 10 under thermal runaway are both lower, a/B is 0.2 or more and 0.5 or less, and the effect is better.
It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict.
The above embodiments are only used to illustrate the technical solutions of the present application, and are not used to limit the present application, and various modifications and changes may be made to the present application by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims (50)

1. A jacket member for a battery cell, comprising a non-weak region and a weak region that are integrally formed, the jacket member being provided with a groove portion around which the non-weak region is formed, the weak region being formed at a bottom of the groove portion, the weak region being configured to be broken when the battery cell is discharged from internal pressure;
wherein the average grain size of the weak region is S 1 The average grain size of the non-weakened area is S 2 And satisfies the following conditions: s. the 1 /S 2 ≤0.9。
2. A housing part according to claim 1, characterized in that S 1 /S 2 ≥0.05。
3. The housing part according to claim 1, wherein 0.1 ≦ S 1 /S 2 ≤0.5。
4. A housing part according to claim 1, characterized in that 0.4 μm ≦ S 1 Less than or equal to 75 mu m; preferably, 1 μm. Ltoreq.S 1 ≤10μm。
5. The housing part according to claim 1, wherein 10 μm ≦ S 2 Less than or equal to 150 mu m; preferably, 30 μm. Ltoreq.S 2 ≤100μm。
6. A jacket component according to claim 1, wherein the minimum thickness of the weak area is a such that: A/S is more than or equal to 1 1 Less than or equal to 100; preferably, 5. Ltoreq. A/S 1 ≤20。
7. A jacket component according to claim 1, wherein the minimum thickness of the weakened zone is a and the hardness of the weakened zone is H 1 Satisfies the following conditions: h is not more than 5HBW/mm 1 A is less than or equal to 10000HBW/mm; preferably, the first and second electrodes are formed of a metal,190HBW/mm≤H 1 /A≤4000HBW/mm。
8. the enclosure component of claim 7, wherein 0.02mm ≦ A ≦ 1.6mm; preferably, 0.06 mm.ltoreq.A.ltoreq.0.4 mm.
9. A shell component according to claim 1, wherein said weakened area has a hardness H 1 The hardness of the non-weakened area is H 2 Satisfies the following conditions: h 1 ＞H 2 。
10. A housing part according to claim 9, characterized in that H 1 /H 2 Less than or equal to 5; preferably, H 1 /H 2 ≤2.5。
11. The housing part of claim 9, wherein 5HBW ≦ H 2 ≤150HBW。
12. The housing part of claim 7, wherein 5HBW ≦ H 1 ≤200HBW。
13. A shell component according to claim 1, wherein the minimum thickness of the weakened area is a and the minimum thickness of the non-weakened area is B, such that: A/B is more than or equal to 0.05 and less than or equal to 0.95; preferably, 0.12. Ltoreq. A/B. Ltoreq.0.8; preferably, 0.2. Ltoreq. A/B. Ltoreq.0.5.
14. The enclosure component of claim 13, wherein 0.02mm ≦ A ≦ 1.6mm; preferably, 0.06mm ≦ A ≦ 0.4mm.
15. The enclosure component of claim 13, wherein 1mm ≦ B ≦ 5mm; preferably, B is more than or equal to 1.2mm and less than or equal to 3.5mm; preferably, 2mm B is less than or equal to 3mm.
16. An outer shell component according to claim 1, wherein the outer shell component has a pressure relief area, the trough portion comprising a primary score trough, the score trough being provided along an edge of the pressure relief area, the pressure relief area being configured to be openable bordered by the score trough, the weak area forming a bottom of the score trough.
17. An enclosure component as claimed in claim 16, wherein the enclosure component has a first surface and a second surface arranged opposite, the score groove being recessed from the first surface towards a direction close to the second surface.
18. The exterior part according to claim 1, wherein the exterior part comprises a first surface and a second surface which are oppositely arranged, the groove part comprises a plurality of levels of score grooves which are arranged in sequence in a direction from the first surface to the second surface, and the weak area is formed at a bottom of the score groove of the level one farthest from the first surface;
wherein the shell member has a pressure relief zone, the scored groove of each level being provided along an edge of the pressure relief zone, the pressure relief zone being configured to be openable bordered by the scored groove of the level furthest away from the first surface.
19. A jacket member according to claim 18, wherein the primary score groove furthest from the second surface is recessed from the first surface in a direction towards the second surface.
20. An outer shell component according to claim 16 or 18, wherein the outer shell component comprises first and second oppositely arranged surfaces, the sump portion further comprising a primary countersink, the countersink being recessed from the first surface towards the second surface, the relief region being formed in a bottom wall of the countersink.
21. The housing component according to claim 16 or 18, wherein the housing component comprises a first surface and a second surface which are oppositely arranged, and the gutter portion further comprises a plurality of levels of sinks which are sequentially provided to the housing component in a direction from the first surface to the second surface, the sink of one level which is farthest from the second surface being recessed from the first surface toward a position close to the second surface, and the pressure relief area is formed on a bottom wall of the sink of the one level which is farthest from the first surface.
22. A housing component according to claim 21, wherein the interior space of the sink is a cylinder, prism, frustum, or frustum.
23. An enclosure component as claimed in any one of claims 16-19, wherein the scored groove comprises a first groove section and a second groove section, the first groove section intersecting the second groove section, the first groove section and the second groove section being disposed along an edge of the pressure relief zone.
24. The outer shell component of claim 23, wherein the scored groove further comprises a third groove segment, the first groove segment and the third groove segment being oppositely disposed, the second groove segment intersecting the third groove segment, the first groove segment, the second groove segment, and the third groove segment being disposed along an edge of the pressure relief zone.
25. A shell component according to claim 24, wherein said first, second and third groove segments are connected in series, said first, second and third groove segments defining one said pressure relief zone.
26. The enclosure component of claim 24, wherein the first, second, and third trough segments define two of the pressure relief zones, one on each side of the second trough segment.
27. An exterior part according to any one of claims 16-19, wherein said scored groove is a groove extending along a non-closed trajectory.
28. An enclosure component as claimed in claim 27 wherein the score groove is an arc groove.
29. An enclosure part as claimed in any one of claims 16-19, characterized in that the scored groove is a groove extending along a closed track.
30. An exterior component according to claim 29, wherein the score groove is an annular groove.
31. A shell component according to any one of claims 16-19, wherein the relief zone has an area D such that: 90mm 2 ≤D≤1500mm 2 (ii) a Preferably 150mm 2 ≤D≤1200mm 2 (ii) a Preferably 200mm 2 ≤D≤1000mm 2 (ii) a Preferably 250mm 2 ≤D≤800mm 2 。
32. A housing part according to any one of claims 1-19, wherein the housing part has a first surface and a second surface arranged opposite to each other, the well being recessed from the first surface in a direction towards the second surface, the well forming an outer edge at the first surface, the area of the housing part outside the predetermined distance from the outer edge being the non-weakened area.
33. The enclosure component of claim 32, wherein the predetermined distance is L, satisfying: l =5mm.
34. An enclosure component according to any one of claims 1 to 19, further comprising a transition region connecting the weakened region and the non-weakened region, the average grain size of the transition regionSize S 3 Satisfies the following conditions: s. the 3 ≤S 2 。
35. A housing component according to any one of claims 1 to 19, wherein the housing component is an end cap for closing an opening of a case for accommodating an electrode assembly.
36. A casing component according to any one of claims 1 to 19 wherein the casing component is a case having an opening for accommodating an electrode assembly.
37. The enclosure component of claim 36, wherein the housing includes a plurality of integrally formed wall portions that collectively define an interior space of the housing, at least one of the wall portions being provided with the channel portion.
38. The enclosure component of claim 37, wherein the plurality of wall portions includes a bottom wall and a plurality of side walls surrounding the bottom wall, the enclosure defining the opening at an end opposite the bottom wall;
the bottom wall is provided with the groove part; and/or
At least one of the side walls is provided with the groove portion.
39. A housing component according to claim 36, wherein the housing is a cuboid.
40. A housing component according to any one of claims 1 to 19, wherein the material of the housing component comprises an aluminium alloy.
41. The enclosure component of claim 40, wherein the aluminum alloy comprises the following composition in mass percent: more than or equal to 99.6 percent of aluminum, less than or equal to 0.05 percent of copper, less than or equal to 0.35 percent of iron, less than or equal to 0.03 percent of magnesium, less than or equal to 0.03 percent of manganese, less than or equal to 0.25 percent of silicon, less than or equal to 0.03 percent of titanium, less than or equal to 0.05 percent of vanadium, less than or equal to 0.05 percent of zinc and less than or equal to 0.03 percent of other single elements.
42. The enclosure component of claim 40, wherein the aluminum alloy comprises the following composition in mass percent: more than or equal to 96.7 percent of aluminum, more than or equal to 0.05 percent and less than or equal to 0.2 percent of copper, less than or equal to 0.7 percent of iron, less than or equal to 1.5 percent of manganese, less than or equal to 0.6 percent of silicon, less than or equal to 0.1 percent of zinc, less than or equal to 0.05 percent of other single element components, and less than or equal to 0.15 percent of other total element components.
43. A battery cell, comprising:
a housing component as claimed in any one of claims 1 to 42.
44. The battery cell as recited in claim 43 further comprising a housing having an opening, the housing configured to receive an electrode assembly;
the housing member is an end cap that closes the opening.
45. The battery cell as recited in claim 43 wherein the housing member is a case having an opening for receiving an electrode assembly;
the battery cell also includes an end cap that closes the opening.
46. A battery comprising the cell of any one of claims 43-45.
47. The battery of claim 46, wherein the weakened area is located at a lower portion of the battery cell.
48. The battery as defined in claim 47, wherein the battery cell comprises a casing for housing an electrode assembly, the casing comprising a bottom wall and a plurality of side walls surrounding the bottom wall, the bottom wall being integrally formed with the side walls, the casing forming an opening at an end opposite the bottom wall, the weakened zone being located at the bottom wall.
49. The cell defined in claim 47, wherein the cell includes an end cap for closing an opening of a casing for receiving the electrode assembly, the weakened section being located in the end cap.
50. An electrical device comprising the battery of any one of claims 46-49.
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