WO2023050236A1 - 泄压机构、电池单体、电池、用电装置及其制造方法 - Google Patents

泄压机构、电池单体、电池、用电装置及其制造方法 Download PDF

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Publication number
WO2023050236A1
WO2023050236A1 PCT/CN2021/121962 CN2021121962W WO2023050236A1 WO 2023050236 A1 WO2023050236 A1 WO 2023050236A1 CN 2021121962 W CN2021121962 W CN 2021121962W WO 2023050236 A1 WO2023050236 A1 WO 2023050236A1
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WO
WIPO (PCT)
Prior art keywords
pressure relief
relief mechanism
battery cell
battery
pressure
Prior art date
Application number
PCT/CN2021/121962
Other languages
English (en)
French (fr)
Inventor
黄守君
郑于炼
王鹏
陈新祥
刘彦宇
Original Assignee
宁德时代新能源科技股份有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
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Application filed by 宁德时代新能源科技股份有限公司 filed Critical 宁德时代新能源科技股份有限公司
Priority to EP21957719.4A priority Critical patent/EP4207459A1/en
Priority to PCT/CN2021/121962 priority patent/WO2023050236A1/zh
Priority to JP2023519719A priority patent/JP2023546798A/ja
Priority to CN202180085647.7A priority patent/CN116670921A/zh
Priority to KR1020237015099A priority patent/KR20230079208A/ko
Publication of WO2023050236A1 publication Critical patent/WO2023050236A1/zh
Priority to US18/303,017 priority patent/US20230261313A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/30—Arrangements for facilitating escape of gases
    • H01M50/342—Non-re-sealable arrangements
    • H01M50/3425—Non-re-sealable arrangements in the form of rupturable membranes or weakened parts, e.g. pierced with the aid of a sharp member
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/102—Primary casings; Jackets or wrappings characterised by their shape or physical structure
    • H01M50/103—Primary casings; Jackets or wrappings characterised by their shape or physical structure prismatic or rectangular
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/20—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders
    • H01M50/249—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders specially adapted for aircraft or vehicles, e.g. cars or trains
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/30—Arrangements for facilitating escape of gases
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/30—Arrangements for facilitating escape of gases
    • H01M50/317—Re-sealable arrangements
    • H01M50/325—Re-sealable arrangements comprising deformable valve members, e.g. elastic or flexible valve members
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/30—Arrangements for facilitating escape of gases
    • H01M50/342—Non-re-sealable arrangements
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/30—Arrangements for facilitating escape of gases
    • H01M50/375—Vent means sensitive to or responsive to temperature
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/572—Means for preventing undesired use or discharge
    • H01M50/574—Devices or arrangements for the interruption of current
    • H01M50/578—Devices or arrangements for the interruption of current in response to pressure
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2200/00—Safety devices for primary or secondary batteries
    • H01M2200/20—Pressure-sensitive devices
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2220/00—Batteries for particular applications
    • H01M2220/20—Batteries in motive systems, e.g. vehicle, ship, plane
    • 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

Definitions

  • the present application relates to the field of batteries, in particular to a pressure relief mechanism, a battery cell, a battery, an electrical device and a manufacturing method thereof.
  • the battery is usually equipped with a pressure relief mechanism.
  • the pressure relief mechanism When the air pressure or temperature inside the battery increases to a certain level, the pressure relief mechanism will be opened in time, and the internal gas will be released through the pressure relief mechanism, thereby preventing the battery from exploding.
  • the air pressure inside the battery is lower than the design actuation pressure of the pressure relief mechanism, and the pressure relief mechanism sometimes fails, resulting in a reduction in the service life of the pressure relief mechanism and affecting the safety performance of the battery .
  • the embodiment of the present application provides a pressure relief mechanism, a battery cell, a battery, an electrical device, and a manufacturing method of the pressure relief mechanism, which can prevent the pressure relief mechanism from failing when the air pressure is low, ensure the service life of the pressure relief mechanism, and improve Battery safety performance.
  • a pressure relief mechanism which is arranged on the casing plate of the battery cell, and includes: a connecting part, which is located in the outer peripheral area of the pressure relief mechanism, and is used for connecting with the casing plate; a first part , one end of which is connected to the connection part, and the other end protrudes obliquely toward the inside of the battery cell; a weak part, which is connected to the protruding end of the first part; and a second part, which has a A shape protruding in the direction of the inside of the body, the outer edge area of which is connected to the weakened part, wherein when the internal pressure or temperature of the battery cell is lower than a first predetermined value, the weakened part is subjected to the pressure of the first part and/or extrusion of the second part.
  • the first part under the action of the air pressure inside the battery cell, the first part protruding obliquely toward the inside of the battery cell and the second part having a shape protruding toward the inside of the battery cell Moving or tending to move away from the inside of the battery cell, the first part is constrained by the connecting portion. Therefore, when the air pressure or temperature inside the battery cell is small, specifically, when it is less than the first predetermined value, the contour of the side of the battery cell inside the pressure relief mechanism has a reduced circumference and shrinks toward the center of the pressure relief mechanism.
  • the tendency is to make the weak part squeezed by the first part and/or the second part, which can suppress the cracking of the weak part, thereby preventing the pressure relief mechanism from creeping failure under the condition of low air pressure, and effectively prolonging the life of the pressure relief mechanism.
  • the first portion and the second portion when the air pressure or temperature inside the battery cell further increases to greater than or equal to the first predetermined value, the first portion and the second portion further move away from the inside of the battery cell, so that The second part of the protruding shape in the internal direction is deformed into a protruding shape away from the internal direction of the battery cell.
  • the weak part is stretched by the first part and/or the second part, which promotes the cracking of the weak part and realizes rapid release. pressure, more effectively prevent the battery from exploding.
  • the thickness of the first portion is greater than or equal to the thickness of the second portion. Since the second part is relatively thin and the first part is relatively thick, when the internal air pressure or temperature of the battery cell further increases to greater than or equal to the first predetermined value, the second part becomes more easily and quickly to move away from the battery cell.
  • the shape of the inner direction is protruding and produces a large deformation, while the first part produces a small deformation, so as to stretch the weak part more effectively, promote the cracking of the weak part, realize rapid pressure release, and avoid the explosion of the battery .
  • the weakened portion when the internal temperature or air pressure of the battery cell is greater than or equal to a second predetermined value, the weakened portion is actuated so that the internal pressure of the battery cell is released through the pressure relief mechanism. That is, the second predetermined value is the burst pressure or temperature of the pressure relief mechanism, and when the internal temperature or air pressure of the battery cell is greater than or equal to the second predetermined value, the weak part is actuated to realize the pressure relief function.
  • the second portion further includes a middle region connected to the outer edge region, and the middle region is substantially parallel to the portion of the housing plate where the pressure relief mechanism is disposed.
  • the middle region is substantially parallel to the end cap, the second part does not deform too violently, so that cracking does not occur easily in the second part, and the risk of actuation from a position other than the weak part can be reduced.
  • the second portion is provided with a thin-walled region.
  • Providing the thin-walled area can make the second part more easily deformed under the action of air pressure.
  • setting the thin-walled area can easily realize the deformation of the second part and facilitate the actuation of the weak part.
  • a reinforcing structure is provided on the first portion.
  • the reinforcement structure can improve the strength of the first part, strengthen the support for the weak part, prevent unnecessary deformation of the first part, ensure that the first part can effectively squeeze the weak part under a small air pressure or temperature, and restrain the weak part. Cracking prevents the pressure relief mechanism from actuating when the battery cell is in normal operation, effectively prolonging the life of the pressure relief mechanism.
  • the reinforcement structure includes a raised reinforcement rib disposed on a side surface of the first portion.
  • the reinforcing rib can increase the thickness of a partial area of the first part and improve the strength of the first part.
  • the reinforcement structure further includes a recess provided on the other side surface of the first part at a position corresponding to the reinforcement rib.
  • the concave part can improve the strength of the first part, and the reinforcing rib and the concave part can be formed by stamping, which is easy to manufacture.
  • the connecting portion is ring-shaped and includes two straight portions and two arc-shaped portions respectively connected to the ends of the two straight portions, and the reinforcing structure is located at the end corresponding to the straight portions. on the first part.
  • the strength of the first part can be improved more effectively by disposing the reinforcing structure at the position corresponding to the straight part.
  • the profile of the pressure relief mechanism is a racetrack shape, which can achieve a larger exhaust area, which is beneficial to pressure relief.
  • the thickness of at least a partial area of the weakened portion is smaller than the thickness of the first portion and the second portion. That is, the thickness of a part of the weakened portion is not reduced, so when the weakened portion ruptures, the second portion does not fly out with discharge such as air currents.
  • the weakened portion is a groove.
  • the groove structure can be formed by stamping and is easy to manufacture.
  • the present application provides a battery cell, including the pressure relief mechanism in the first aspect.
  • the present application provides a battery, including: the battery cell in the second aspect.
  • the present application provides an electrical device, including: the battery of the third aspect, where the battery is used to provide electrical energy.
  • a method for manufacturing a pressure relief mechanism including: providing a connecting portion, which is arranged on the outer peripheral area of the pressure relief mechanism, for connecting with the shell plate; providing a first part, and connecting one end of the connected with the connection part, and the other end protrudes obliquely toward the inside of the battery cell; a weak part is provided to connect it to the protruding end of the first part; and a second part is provided to have a The shape protruding in the inner direction of the cell connects the outer edge area with the weak portion; wherein, when the internal pressure or temperature of the battery cell is lower than a first predetermined value, the weak portion is subjected to the pressure of the first part and the and/or extrusion of said second portion.
  • FIG. 1 is a schematic structural view of a vehicle in some embodiments of the present application.
  • FIG. 2 is a schematic structural view of batteries in some embodiments of the present application.
  • FIG. 3 is an exploded view of a battery cell in some embodiments of the present application.
  • Fig. 4 is the front view of the end cap of some embodiments of the present application.
  • Fig. 5 is a-a sectional view of Fig. 4;
  • Fig. 6 is a perspective view of a pressure relief mechanism in some embodiments of the present application.
  • Fig. 7 is a view of the pressure relief mechanism of Fig. 6;
  • Fig. 8 is a b-b sectional view of Fig. 7;
  • Fig. 9 is an enlarged view of area X1 in Fig. 8;
  • FIG. 10 is a perspective view of the pressure relief mechanism when the internal pressure or temperature of the battery cell is less than a first predetermined value
  • Figure 11 is a sectional view of the pressure relief mechanism
  • Fig. 12 is an enlarged view of the area X2 in Fig. 11;
  • Fig. 13 is a perspective view when the internal air pressure or temperature of the battery cell rises to greater than or equal to the first predetermined value, and the second part becomes an upwardly protruding state;
  • Figure 14 is a sectional view of the pressure relief mechanism
  • Fig. 15 is an enlarged view of area X3 in Fig. 14;
  • Fig. 16 is a perspective view when the internal pressure or temperature of the battery cell rises to greater than or equal to a second predetermined value, and the pressure relief mechanism is about to rupture;
  • Figure 17 is a sectional view of the pressure relief mechanism
  • FIG. 18 is an enlarged view of the area X4 in FIG. 17 .
  • Fig. 19 is an enlarged view of the part corresponding to the area X1 in the pressure relief mechanism of some embodiments of the present application, showing a modified example of the pressure relief mechanism;
  • Figure 20 is the initial state of the pressure relief mechanism of the prior art
  • Fig. 21 is an enlarged view of area X5 in Fig. 20;
  • Fig. 22 is the state of the pressure relief mechanism of the prior art at a lower air pressure
  • Fig. 23 is an enlarged view of area X6 in Fig. 22;
  • Fig. 24 shows the state of the cracking of the pressure relief mechanism in the prior art
  • Fig. 25 is an enlarged view of the middle area X7 in Fig. 24;
  • Fig. 26 is a partially enlarged view of a pressure relief mechanism according to another embodiment of the present application.
  • Fig. 27 is a perspective view of a pressure relief mechanism in some other embodiments of the present application.
  • Fig. 28 is an enlarged view of area X9 in Fig. 27;
  • Fig. 29 is a perspective view of the pressure relief mechanism in Fig. 27 in another direction;
  • Fig. 30 is an enlarged view of the area X10 in Fig. 29;
  • Fig. 31 is a front view of the pressure relief mechanism in Fig. 27 on the side away from the battery cell;
  • Fig. 32 is a cross-sectional view of the pressure relief mechanism in Fig. 31;
  • Fig. 33 is another cross-sectional view of the pressure relief mechanism in Fig. 31;
  • Fig. 34 is a schematic flowchart of a manufacturing method of a pressure relief mechanism according to some embodiments of the present application.
  • End cap 10 housing 20, electrode terminal 30, electrode assembly 40, main body 41, tab 42, positive tab 421, negative tab 422, housing plate 50, connecting member 60;
  • Pressure relief mechanism 100 connecting part 101, first part 102, weak part 103, second part 104; outer edge area 1041, middle area 1042, thin wall area 1043;
  • Controller 300 Motor 400, battery 500;
  • Box 600 a first shell 601, a second shell 602;
  • connection In the description of this application, it should be noted that, unless otherwise clearly stipulated and limited, the terms “installation”, “connection”, “connection” and “attachment” should be understood in a broad sense, for example, it may be a fixed connection, It can also be detachably connected or integrally connected; it can be directly connected or indirectly connected through an intermediary, and it can be internal communication between two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in this application according to specific situations.
  • Multiple appearing in this application refers to more than two (including two), similarly, “multiple groups” refers to more than two groups (including two groups), and “multi-piece” refers to more than two (Includes two pieces).
  • the battery cells may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, which are not limited in the embodiments of the present application.
  • the battery cell can be in the form of a cylinder, a flat body, a cuboid or other shapes, which is not limited in this embodiment of the present application.
  • Battery cells are generally divided into three types according to packaging methods: cylindrical battery cells, square square battery cells and pouch battery cells, which are not limited in this embodiment of the present application.
  • the battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.
  • the battery mentioned in this application may include a battery module or a battery pack, and the like.
  • Batteries generally include a case for enclosing one or more battery cells. The box can prevent liquid or other foreign objects from affecting the charging or discharging of the battery cells.
  • the battery cell includes an electrode assembly and an electrolyte, and the electrode assembly is composed of a positive electrode sheet, a negative electrode sheet, and a separator.
  • a battery cell works primarily by moving metal ions between the positive and negative plates.
  • the positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer.
  • the positive electrode active material layer is coated on the surface of the positive electrode current collector.
  • the current collector without the positive electrode active material layer protrudes from the current collector coated with the positive electrode active material layer.
  • the current collector coated with the positive electrode active material layer serves as the positive electrode tab.
  • the material of the positive electrode current collector can be aluminum, and the positive electrode active material can be lithium cobaltate, lithium iron phosphate, ternary lithium or lithium manganate.
  • the negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer.
  • the negative electrode active material layer is coated on the surface of the negative electrode current collector.
  • the current collector coated with the negative electrode active material layer serves as the negative electrode tab.
  • the material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon or silicon.
  • the number of positive pole tabs is multiple and stacked together, and the number of negative pole tabs is multiple and stacked together.
  • the material of the isolation film can be PP or PE.
  • the electrode assembly may be a wound structure or a laminated structure, which is not limited in the embodiment of the present application.
  • the protection measures include at least the switching element, the selection of an appropriate isolation diaphragm material, and the pressure relief mechanism.
  • the switching element refers to the element that stops charging or discharging the battery when the temperature or resistance inside the battery cell reaches a certain threshold.
  • the separator is used to isolate the positive electrode and the negative electrode. When the temperature rises to a certain value, it can automatically dissolve the micron-scale (or even nano-scale) micropores attached to it, so that metal ions cannot pass through the separator and terminate the battery. The internal reaction of the monomer.
  • the pressure relief mechanism refers to an element or part that is activated to release the internal pressure or temperature when the internal pressure or temperature of the battery cell reaches a predetermined threshold.
  • the value of the threshold varies according to different design requirements, depending on one or more materials of the positive pole piece, the negative pole piece, the electrolyte and the separator in the battery cell.
  • the pressure relief mechanism may be in the form of an explosion-proof valve, an air valve, a pressure relief valve or a safety valve, and specifically may be a pressure-sensitive or temperature-sensitive element or structure.
  • the pressure relief mechanism acts or the weak structure provided in the pressure relief mechanism is broken and cracked, thereby forming an opening or channel for internal pressure or temperature release.
  • the "activation" mentioned in this application means that the pressure relief mechanism is activated or activated to a certain state, so that the internal pressure and temperature of the battery cells can be released.
  • Actions by the pressure relief mechanism may include, but are not limited to, at least a portion of the pressure relief mechanism rupture, shatter, be torn, or open, among others.
  • the pressure relief mechanism When the pressure relief mechanism is actuated, the high-temperature and high-pressure material inside the battery cell will be discharged from the actuated part as discharge. In this way, the pressure and temperature of the battery cells can be released under the condition of controllable pressure or temperature, so as to avoid potential more serious accidents.
  • the emissions from battery cells mentioned in this application include but are not limited to: electrolyte, dissolved or split positive and negative electrodes, fragments of separator, high temperature and high pressure gas generated by reaction, flame, etc.
  • the pressure relief mechanism on the battery cell has an important impact on the safety of the battery. For example, when a short circuit, overcharge, etc. occur, it may cause thermal runaway inside the battery cell, resulting in a sudden increase in pressure or temperature. In this case, the internal pressure and temperature can be released to the outside through the actuation of the pressure relief mechanism, so as to prevent the battery cells from exploding and igniting.
  • the present application provides a pressure relief mechanism, which includes a first part with one end protruding obliquely toward the inside of the battery cell, and a second part with a shape protruding toward the inside of the battery cell.
  • the second part moves away from the inside of the battery cell, while the first part is restrained by the connecting part and tends to move away from the inside of the battery cell. Therefore, when the air pressure or temperature inside the battery cell is small, specifically, when it is lower than the first predetermined value, the contour of the side of the battery cell inside the pressure relief mechanism has a tendency to decrease in circumference and shrink toward the center of the pressure relief mechanism.
  • the trend is to make the weak part be squeezed by the first part and/or the second part, suppress the cracking of the weak part, prevent the pressure relief mechanism from cracking when the air pressure is small, and effectively prolong the life of the pressure relief mechanism.
  • the first predetermined value is defined as an air pressure or temperature value at which the first portion and/or the second portion changes from a state of pressing the weak portion to a state of stretching the weak portion.
  • batteries such as mobile phones, portable devices, notebook computers, battery cars, electric toys, electric tools, electric vehicles, ships and spacecraft, etc.
  • spacecraft include Airplanes, rockets, space shuttles and spaceships, etc.
  • FIG. 1 is a schematic structural diagram of a vehicle 800 according to an embodiment of the present application.
  • the vehicle 800 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle.
  • a motor 400 , a controller 300 and a battery 500 may be provided inside the vehicle, and the controller 300 is used to control the battery 500 to supply power to the motor 400 .
  • the battery 500 may be provided at the bottom or front or rear of the vehicle.
  • the battery 500 can be used for power supply of the vehicle.
  • the battery 500 can be used as the operating power source of the vehicle for the circuit system of the vehicle 800 , for example, for the starting, navigation and working power requirements of the vehicle 800 during operation.
  • the battery 500 can not only be used as an operating power source for the vehicle 800 , but can also be used as a driving power source for the vehicle 800 , replacing or partially replacing fuel oil or natural gas to provide driving power for the vehicle 800 .
  • the battery may include multiple battery cells, wherein the multiple battery cells may be connected in series, in parallel or in parallel, and the hybrid connection refers to a mixture of series and parallel connections. Batteries can also be referred to as battery packs.
  • a plurality of battery cells can be connected in series, parallel or mixed to form a battery module, and then a plurality of battery modules can be connected in series, parallel or mixed to form a battery. That is to say, multiple battery cells can directly form a battery, or form a battery module first, and then form a battery from the battery module.
  • FIG. 2 is a schematic structural diagram of a battery 500 according to an embodiment of the present application.
  • the battery 500 may include a plurality of battery cells 1 .
  • the battery 500 may also include a box body 600 (or called a cover body), the box body 600 is a hollow structure, and a plurality of battery cells 1 are accommodated in the box body 600 .
  • the box body 600 may include a first shell 601 and a second shell 602 , and the first shell 601 and the second shell 602 are fastened together.
  • the shapes of the first casing 601 and the second casing 602 can be determined according to the combined shape of a plurality of battery cells 1 , and each of the first casing 601 and the second casing 602 has an opening.
  • both the first housing 601 and the second housing 602 can be hollow cuboids and one of their faces is an open face, the opening of the first housing 601 and the opening of the second housing 602 are arranged oppositely, and the opening of the first housing 601 and the second housing 601 602 snap together to form a box with a closed chamber.
  • a plurality of battery cells 1 are connected in parallel or in series or combined in parallel and placed in a box formed by fastening the first casing 601 and the second casing 602 .
  • the number of battery cells 1 can be set to any value. Multiple battery cells 1 can be connected in series, in parallel or in parallel to achieve greater capacity or power. Since the number of battery cells 1 included in each battery 500 may be large, in order to facilitate installation, the battery cells 1 may be arranged in groups, and each group of battery cells 1 constitutes a battery module. The number of battery cells 1 included in the battery module is not limited and can be set according to requirements. For example, a battery may include a plurality of battery modules, and these battery modules may be connected in series, in parallel or in parallel.
  • FIG. 3 is an exploded view of a battery cell 1 in some embodiments of the present application.
  • FIG. 4 is a top view of an end cap 10 according to some embodiments of the present application.
  • Fig. 5 is a cross-sectional view along the arrow A direction at the line a-a in Fig. 4 .
  • the battery cell 1 includes a shell plate 50 and an electrode assembly 40 disposed in the shell plate 50
  • the shell plate 50 includes an end cap 10 and a shell 20
  • the shell 20 has an opening
  • the electrode assembly 40 It is disposed in the housing 20 through the opening of the housing 20 .
  • the electrode assembly 40 includes a main body 41 and a tab 42 extending from the main body 41 .
  • the main body part 41 includes a positive pole piece, a negative pole piece and a separator.
  • the main body 41 may be a coiled structure formed by winding a positive pole piece, a separator and a negative pole piece, or a laminated structure formed by stacking a positive pole piece, a separator and a negative pole piece.
  • the positive pole tab 421 and the negative pole tab 422 can be located on the same side of the main body 41 , or can be located on opposite sides of the main body 41 respectively.
  • FIG. 3 it exemplarily shows the situation that the positive pole tab 421 and the negative pole tab 422 are located on the same side of the main body 41 .
  • the end cap 10 covers the opening of the casing 20 to form a closed space for accommodating the electrode assembly 40 and the electrolyte, which may be an electrolytic solution.
  • the pressure relief mechanism 100 is arranged in the approximate middle of the end cap 10, but according to the arrangement and position of the electrode assembly, the pressure relief mechanism 100 can also be arranged in Other positions of the housing plate 50 .
  • Two electrode terminals 30 are also provided on the end cap 10 , and the electrode terminals 30 are used for electrical connection with the tabs 42 , for outputting electric energy of the battery cell 1 , or for connecting to an external power source to charge the battery cell.
  • the pressure relief mechanism 100 is located between the two electrode terminals 30 .
  • the battery cell 1 further includes a connection member 60 through which the electrode terminal 30 and the tab 42 are electrically connected.
  • FIG. 6 is a perspective view of a pressure relief mechanism 100 according to some embodiments of the present application.
  • FIG. 7 is a view of the side of the pressure relief mechanism 100 facing the interior of the battery cell.
  • Fig. 8 is a sectional view along the arrow B direction at the line b-b in Fig. 7 .
  • FIG. 9 is an enlarged view of the area X1 in FIG. 8 .
  • the pressure relief mechanism 100 includes a connecting portion 101 , a first portion 102 , a weak portion 103 and a second portion 104 .
  • the connecting portion 101 is located at the outer peripheral area of the pressure relief mechanism 100 and is used for connecting with the end cap 10 in FIG. 3 , FIG. 4 , and FIG. 5 .
  • the connecting part 101 includes two straight parts 1011 and two arc parts 1012 respectively connected to ends of the two straight parts 1011 , and the whole is in the shape of a racetrack.
  • one end of the first part 102 is connected to the connecting portion 101 , and the other end protrudes obliquely toward the electrode assembly 40 inside the battery cell 1 , that is, downward in FIG. 3 .
  • the weak portion 103 is connected to the extended end of the first portion 102 .
  • the second part 104 has a shape protruding toward the inside of the battery cell 1 , and the outer edge region 1041 of the second part 104 is connected to the weak portion 103 .
  • the weak portion 103 is pressed by the first portion 102 and/or the second portion 104 .
  • the first portion 102 as a whole is closer to the interior of the battery cell 1 than the connecting portion 101 .
  • the shape of the protruding part of the first part 102 is not particularly limited. In this embodiment, as shown in FIG. The curved shape sticks out.
  • the weak portion 103 is located between the first portion 102 and the second portion 104 , that is, at the protruding end of the first portion 102 , and is closer to the interior of the battery cell 1 than the first portion 102 .
  • the weakened part 103 is weaker than the first part 102 and the second part 104, and the weakened part 103 activates the pressure release when the pressure is released.
  • the second part 104 is the part with the largest area in the pressure relief mechanism 100, located in the middle of the pressure relief mechanism 100, including the outer edge region 1041 and the middle region 1042 (see Fig. 8), One end of the outer edge region 1041 is connected to the weak portion 103 , and the other end is connected to the middle region 1042 .
  • the second part 104 is closer to the interior of the battery cell 1 than the weak portion 103 as a whole, and has a shape that protrudes toward the interior of the battery cell 1 , for example, the second portion 104 is an arch that protrudes toward the interior of the battery cell 1 , but can also be irregular convex shapes. As shown in FIG.
  • the outer edge region 1041 of the second part 104 extends obliquely toward the inside of the battery cell, and the extension direction is roughly the same as the direction in which the first part 102 extends, and the middle region 1042 is roughly parallel to the end where the pressure relief mechanism 100 is disposed. Cover 10.
  • the middle region 1042 is substantially parallel to the end cap 10 , the second part 104 will not be deformed too sharply, so that the second part 104 is not easy to be cracked, and the risk of actuation from a position other than the weak portion 103 can be reduced.
  • FIG. 10 is a perspective view of the pressure relief mechanism 100 when the internal pressure or temperature of the battery cell 1 is lower than a first predetermined value.
  • FIG. 11 is a cross-sectional view of the pressure relief mechanism 100 , the cutting position and viewing angle are the same as those in FIG. 8 , please refer to the description in FIG. 8 .
  • FIG. 12 is an enlarged view of the area X2 in FIG. 11 .
  • the internal air pressure or temperature of the battery cell 1 is relatively low.
  • the air pressure is taken as an example below.
  • the air pressure inside the battery cell 1 continues to act on the pressure relief mechanism 100, so that the first part 102, the weak part 103 and the second part 104 move upward or tend to move upward.
  • the position of the weak portion 103 is closer to the interior of the battery cell than the connection portion 101, that is, the position of the weak portion 103
  • the location of the fixing point between the pressure relief mechanism 100 and the end cover 10 is closer to the inside of the battery cell.
  • one end of the first part 102 is constrained by the connection part 101, one end of the first part 102 extending to the inside of the battery cell 1 presses the weak part 103 in the direction of the right arrow in FIG. Prevent the pressure relief mechanism 100 from creeping failure when the battery cell 1 works normally, and effectively prolong the life of the pressure relief mechanism.
  • FIG. 11 and Fig. 12 since the first part 102 is inclined toward the interior of the battery cell 1, the position of the weak portion 103 is closer to the interior of the battery cell than the connection portion 101, that is, the position of the weak portion 103
  • the location of the fixing point between the pressure relief mechanism 100 and the end cover 10 is closer to the inside of the battery cell.
  • one end of the first part 102 is constrained by the connection part
  • the second part 104 moves upwards under the action of air pressure, and the second part 104 squeezes the weak portion 103 in the direction of the left arrow in FIG. Creep failure occurs when the battery cell 1 works normally, effectively prolonging the service life of the pressure relief mechanism 100 .
  • FIG. 13 shows a state diagram of the process in which the internal pressure or temperature of the battery cell 1 rises to greater than or equal to the first predetermined value, and the second part 104 turns upward and protrudes.
  • Fig. 14 is a cross-sectional view of the pressure relief mechanism 100, and the cutting position and viewing angle are the same as those in Fig. 8 and Fig. 11 .
  • FIG. 15 is an enlarged view of the area X3 in FIG. 14 .
  • the second part 104 moves to the top of the weak part 103 as a whole, and the second part 104 changes from the state of squeezing the weak part 103 shown in FIG. 103 cracking, help to achieve rapid pressure relief.
  • the second predetermined value when the second predetermined value is defined, it means the predetermined pressure relief temperature or pressure value of the pressure relief mechanism 100 . That is, when the temperature or pressure inside the battery cell 1 reaches a second predetermined value, the pressure relief mechanism 100 is activated, for example, the weak portion 103 is ruptured, and the internal pressure of the battery cell 1 is released through the pressure relief mechanism 100 .
  • FIG. 16 is a perspective view when the internal pressure or temperature of the battery cell 1 rises to greater than or equal to a second predetermined value and the pressure relief mechanism 100 is about to rupture.
  • Fig. 17 is a cross-sectional view of the pressure relief mechanism 100, and the cutting position and viewing angle are the same as Fig. 8, Fig. 11 and Fig. 14 .
  • FIG. 18 is an enlarged view of the area X4 in FIG. 17 .
  • the first part 102 , the weak part 103 and the second part 104 continue to move upward as a whole, and a greater force is applied to the weak part 103 . stretching force.
  • the first part 102 is constrained by the connection part 101 and moves very little, so the second part 104 and the first part 102 effectively stretch the weak part 103 , causing the weak part 103 to rupture and release the pressure inside the battery cell 1 .
  • FIG. 19 shows a modified example of the pressure relief mechanism 100 in FIG. 9 .
  • the thickness of the first portion 102 is greater than or equal to the thickness of the second portion 104 .
  • the thinner second part 104 will more easily and quickly turn away from the interior of the battery cell 1
  • FIG. 20 is a cross-sectional view of a pressure relief mechanism in the prior art, and the cutting position and viewing angle are the same as those in FIG. 8 .
  • FIG. 21 is an enlarged view of the area X5 in FIG. 20 .
  • the pressure relief mechanism 200 of the prior art shown in FIG. 20 and FIG. 21 includes a connection part 201 , a first part 202 , a weak part 203 and a second part 204 .
  • the outline shape of the pressure relief mechanism 200 is set to be substantially the same as that of the pressure relief mechanism 100 of the present application.
  • the first part 202 and the second part 204 are located on the same plane as the connecting part 201 , the first part 202 of the pressure relief mechanism 200 does not protrude into the battery cell, and the second part 204 does not protrude into the battery cell 1 .
  • FIG. 22 shows the state of the pressure relief mechanism 200 in the prior art under the action of a relatively low air pressure (the cutting position and viewing angle are the same as those in Fig. 20).
  • FIG. 23 is an enlarged view of the area X6 in FIG. 22 .
  • the pressure relief mechanism 200 is affected by the air pressure inside the battery cell when the battery cell is working normally.
  • the first part 202 and the second part 204 move away from the inside of the battery cell.
  • the continuous action of the air pressure inside the battery cell Next, the first part 202 and the second part 204 respectively continuously stretch the weak part 203 along the direction of the arrow in FIG. 23 , so the weak part 203 may crack under the action of a small air pressure when the battery cell is working normally.
  • FIG. 24 shows the cracked state of the pressure relief mechanism in the prior art (the cutting position and viewing angle are the same as those in Fig. 20).
  • FIG. 25 is an enlarged view of the middle area X7 in FIG. 24 .
  • the pressure relief mechanism 200 is subjected to the internal air pressure of the battery cell for a long time, and the weak portion 203 continues to be stretched by the first part 202 and the second part 204 to generate creep, so that the first part 202 and the second part 204 continue to move upward, As a result, the weak portion 203 ruptures when the battery cell is in normal operation, and creep failure occurs.
  • FIG. 26 is a partially enlarged view of a cross-sectional view of a pressure relief mechanism in another embodiment of the present application (the cutting position and viewing angle are the same as those in FIG. 8 ).
  • a thin-walled region 1043 is provided on the second portion 104 , and the thickness of the thin-walled region 1043 is smaller than that of other regions in the second portion 104 .
  • the thin-walled area 1043 is an annular groove opening toward the inside of the battery cell 1 .
  • the second part 104 When the size of the pressure relief mechanism 100 is small, the second part 104 needs to be set thin enough to ensure that the second part 104 protrudes away from the inside of the battery cell 1 when the air pressure or temperature is greater than or equal to the first predetermined value. state to promote the cracking of the weak portion 103 and achieve the same pressure relief effect as the large-sized pressure relief mechanism.
  • a thin-walled area 1043 can be set in the second part 104, and under the action of air pressure, compared with other areas of the second part 104, the thin-walled area 1043 is more likely to deform, so that the second part 104 is easy to change to the opposite direction. The state in which the battery cell 1 protrudes toward the inside.
  • the thin-walled region 1043 of the present application is not limited to the above structure, and may also be an annular groove opening away from the inside of the battery cell 1 , or may be provided with annular grooves on both the upper surface and the lower surface of the second part 104 .
  • the shape of the thin-walled area 1043 is not particularly limited, and may be arc-shaped, linear or other shapes instead of a ring.
  • the thin-walled area 1043 is preferably arranged symmetrically on the second part 104 .
  • the number of thin-walled regions 1043 is not particularly limited, and can be appropriately set according to needs.
  • FIG. 27 is a view of the side of the pressure relief mechanism 100 facing away from the interior direction of the battery cell 1 in another embodiment of the present application.
  • FIG. 28 is an enlarged view of a region X9 in FIG. 27 .
  • FIG. 29 is a perspective view of the other side of the pressure relief mechanism 100 of FIG. 27 .
  • FIG. 30 is an enlarged view of a region X10 in FIG. 29 .
  • FIG. 31 is a plan view of the pressure relief mechanism 100 in FIG. 27 on the side away from the interior direction of the battery cell 1 .
  • FIG. 32 is a cross-sectional view of the pressure relief mechanism 100 in FIG. 31 (the cutting position and viewing angle are the same as those in FIG. 8 ).
  • FIG. 33 is a cross-sectional view along the arrow L direction of the pressure relief mechanism 100 in FIG. 31 at the line l-l.
  • the first portion 102 is provided with a reinforcing structure 1021 .
  • the pressure relief mechanism 100 has a larger area and greater air pressure, even when the air pressure is low, the first part 102 will move a lot and cannot effectively squeeze the weak portion 103 . If the thickness of the first part 102 is increased to prevent unnecessary deformation, the thickness difference between the first part and the designed weak part 103 will be too large, making it difficult to form the weak part 103 with the desired thickness, resulting in increased manufacturing cost. Therefore, by providing the reinforcing structure 1021, the strength of the first part 102 can be enhanced, and it is easy to process.
  • a raised rib 1021b is provided on one side surface of the first portion 102 .
  • the reinforcing rib 1021b can be arranged on the side of the first part 102 facing away from the inside of the battery cell 1 , or can be arranged on the side of the first part 102 facing the inside of the battery cell 1 .
  • the other side surface of the first part 102 is provided with a recess 1021a at a position corresponding to the reinforcing rib 1021b, specifically as shown in FIG.
  • the depth of the concave portion 1021a is greater than the protruding height of the reinforcing rib 1021b, and the width of the opening of the concave portion 1021a (in the left-right direction in FIG. 33 ) is smaller than the width of the reinforcing rib 1021b. Therefore, two locally thickened regions 1021c are formed on the left and right sides of the concave portion 1021a, and the thickness of the locally thickened regions 1021c is greater than that of other positions in the first portion 102 .
  • Such a structure does not increase the overall volume of the first part 102, but can improve the strength of the first part 102 in the main direction of force.
  • the reinforcing structure 1021 with such a structure can be formed by stamping, which is easy to manufacture.
  • the strengthening structure 1021 may also be a structure in which the strength of a part of the first part 102 is chemically treated.
  • the connecting portion 101 is an annular plate-shaped structure, and can be connected to the end cover 10 by, for example, welding.
  • the welding position can be on the outside of the end cap 10 ; when the first portion 102 extends beyond the thickness of the end cap, the welding position can also be on the inside of the end cap 10 .
  • the connection part 101 includes two straight parts 1011 and two arc parts 1012 respectively connected to ends of the two straight parts 1011 , and the above-mentioned reinforcing structure 1021 is located on the first part 102 corresponding to the straight parts 1011 .
  • the reinforcing structure 1021 is arranged at a position corresponding to the straight portion 1011 to more effectively improve the stability of the first portion 102. strength.
  • the strong structure 1021 may also be arranged at a position corresponding to the arc portion 1012 as required.
  • the two straight parts 1011 are substantially parallel to each other, and the connecting part 101 formed by the two straight parts 1011 and the two arc parts 1012 is in the shape of a circular racetrack as a whole.
  • connection part 101 of this embodiment is in the shape of a circular racetrack.
  • the pressure relief mechanism 100 is applied to a small-sized battery cell, for the same length and width area, the pressure relief The exhaust area is larger, which can expel the gas faster.
  • the arrangement of the pressure relief mechanism 100 on the end cap 10 is as shown in FIG.
  • the electrode terminals 30 near the two sides of the pressure relief mechanism 100 more specifically, the line connecting the arc midpoints of the two arc portions 1012 and the line connecting the two electrode terminals 30 are on the same straight line.
  • the line connecting the arc midpoints of the two arc portions 1012 and the line connecting the two electrode terminals 30 are all on the section line a-a shown in FIG. 4 .
  • the pressure relief mechanism 100 can also be arranged in such a manner that the straight line portion is closer to the electrode terminal 30 as shown in FIG. 3 .
  • the thickness of at least part of the weakened portion 103 is smaller than the thickness of the first portion 102 and the second portion 104, that is, the thickness of not all parts of the weakened portion 103 is smaller than the thickness of the first portion 102 and the second portion 104, Only a part of the weak portion 103 has a thickness smaller than that of the first part 102 and the second part 104 , and the thickness of other parts may be equal to or even greater than that of the first part 102 and/or the second part 104 .
  • the second portion 104 Since the thickness of a part of the weakened portion 103 is not reduced, when the weakened portion 103 is ruptured, the second portion 104 will not fly out with the discharge such as airflow.
  • the weak portion 103 is a groove structure, for example, an annular groove structure opening to one side inside the battery cell 1 .
  • the annular groove structure may include a plurality of discontinuous grooves, that is, the thickness of a partial region meeting the weak portion 103 is smaller than the thickness of the first portion 102 and the second portion 104 .
  • the weak part 103 is a groove structure, the thickness and strength of the weak part 103 are smaller than the first part 102 and the second part 104 , so the weak part 103 is easy to crack.
  • the weak portion 103 is not limited to the groove structure, as long as the strength of the weak portion 103 is sufficiently smaller than the structures of the first portion 102 and the second portion 104 .
  • the weakened portion 103 may be a structure in which the weakened portion 103 is softened by chemical treatment to reduce its strength.
  • a battery 500 is also provided, including the above-mentioned battery cell 1 .
  • an electrical device including the battery 500 described above, which is used to provide electrical energy.
  • the electrical device may be the vehicle 800 shown in FIG. 1 , or may be a ship or a spacecraft.
  • the present application also provides a manufacturing method of the pressure relief mechanism.
  • FIG. 34 shows a flowchart of a manufacturing method of the pressure relief mechanism 100 according to an embodiment of the present application.
  • the manufacturing method of this embodiment includes:
  • Step S1 providing the connecting part 101, which is arranged on the outer peripheral area of the pressure relief mechanism 100, for connecting with the end cover 10;
  • Step S2 providing the first part 102, connecting one end of it to the connecting part 101, and the other end protruding obliquely toward the inside of the battery cell;
  • Step S3 providing a weak portion 103 and connecting it to the protruding end of the first part 102;
  • Step S4 providing the second part 104 so that it has a shape protruding toward the inside of the battery cell, so that its outer edge area is connected to the weak portion 103; wherein, when the internal pressure or temperature of the battery cell is less than the first predetermined value , the weak portion 103 is pressed by the first portion 102 and/or the second portion 104 .
  • connection part 101 , the first part 102 and the second part 104 are integrally formed by using a metal material through a mold.
  • the metal material is, for example, aluminum foil, copper foil, or the like.
  • the first part 102 and the second part 104 are not distinguished in shape.
  • the groove-shaped weak portion 103 is formed on the whole of the first part 102 and the second part 104 by punching or cutting at a pre-designed position to obtain the pressure relief mechanism 100 as shown in FIGS. 6 to 10 .
  • the thickness of the first part 102 By selecting appropriate materials, setting the thickness of the first part 102, the protruding length of the first part 102, the area of the second part 104, the thickness of the second part 104, the thickness of the weak part 103 and other parameters, it can be realized in the battery cell.
  • the weak portion 103 is squeezed by the first part 102 and the second part 104 when the internal pressure or temperature of the body is lower than the first predetermined value.
  • the design of specific parameters is properly set according to the size of the pressure relief mechanism, etc., and the present application does not repeat them here.
  • the thickness of the first portion 102 is set to be greater than or equal to the thickness of the second portion 104 .
  • this can be achieved by adjusting the shape of the forming die.
  • the second part 104 is provided with a thin-walled area 1043 as shown in FIG. 26 to facilitate the deformation of the second part 104 .
  • the thin-walled area 1043 can be formed by punching or cutting the second part 104 , or can be integrally formed with the second part 104 by setting the shape of the mold.
  • the first part 102 is provided with a reinforcing structure 1021 as shown in FIGS. 27 to 32 to support the weak area 103 .
  • the reinforcing structure 1021 is formed by stamping the first part 102 , and may also be integrally formed with the first part 102 by setting the shape of the mold.

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  • Electrochemistry (AREA)
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  • Engineering & Computer Science (AREA)
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  • Gas Exhaust Devices For Batteries (AREA)
  • Sealing Battery Cases Or Jackets (AREA)
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  • Hybrid Cells (AREA)

Abstract

本申请实施例提供了一种泄压机构, 电池单体电池用电装置及其制造方法泄压机构设置于电池单体的壳体板, 包括：连接部, 其位于所述泄压机构外周边区域, 用于与所述壳体板连接；第一部分，其一端与所述连接部连接, 另一端向电池单体内部方向倾斜伸出；薄弱部, 连接于所述第一部分的所述伸出的一端；以及第二部分, 其具有向电池单体内部方向凸出的形状, 其外边缘区域与所述薄弱部连接，其中, 所述电池单体内部温度或气压小于第一预定值时, 所述薄弱部受到所述第一部分和/或所述第二部分的挤压本申请实施例的技术方案, 能够有效延长泄压机构的寿命。

Description

泄压机构、电池单体、电池、用电装置及其制造方法 技术领域
本申请涉及电池领域，具体涉及一种泄压机构、电池单体、电池、用电装置及其制造方法。
背景技术
电池在例如过度充电、被金属导体刺穿极片以及热箱测试等情况下，内部会迅速地积聚热量、气体，从而造成内部的气压增加，严重时甚至会导致电池的膨胀和爆炸。
因此，电池通常设置有泄压机构，当电池内部的气压或温度增加到一定程度时，泄压机构及时打开，内部气体经由泄压机构释放，从而避免电池发生爆炸。现有技术中，即使电池处于正常工作状态，电池内部的气压小于泄压机构的设计致动压力，泄压机构有时也会失效，导致泄压机构的使用寿命减少，对电池的安全性能产生影响。
发明内容
本申请实施例提供一种泄压机构、电池单体、电池、用电装置及泄压机构制造方法，能够防止泄压机构在气压较小的情况下失效，保证泄压机构使用寿命，并提高电池的安全性能。
第一方面，提供了一种泄压机构，设置于电池单体的壳体板，包括：连接部，其位于所述泄压机构外周边区域，用于与所述壳体板连接；第一部分，其一端与所述连接部连接，另一端向电池单体内部方向倾斜伸出；薄弱部，其连接于所述第一部分的所述伸出的一端；以及第二部分，其具有向电池单体内部方向凸出的形状，其外边缘区域与所述薄弱部连接，其中，当所述电池单体内部气压或温度小于第一预定值时，所述薄弱部受到所述第一部分和/或所述第二部分的挤压。
在本申请实施例的泄压机构中，在电池单体内部的气压作用下，向电池单体内部方向倾斜伸出的第一部分、和具有向电池单体内部方向凸出的形状的第二部分向背离电池单体内部方向移动或有向背离电池单体内部方向移动的趋势，第一部分受到连接部的约束。因此，在电池单体内部的气压或温度较小，具体而言，小于第一预定值时，泄压机构的电池单体内部一侧的轮廓存在周长减小、向泄压机构中心收缩的趋势，使薄弱部受到第一部分和/或第二部分的挤压，可以抑制薄弱部的开裂，从而防止泄压机构在气压较小的情况下蠕变失效，有效延长泄压机构的寿命。
在一些实施例中，当电池单体内部的气压或温度进一步增加到大于或等于第一预定值时，第一部分和第二部分进一步向背离电池单体内部方向发生移动，使得具有向电池单体内部方向凸出的形状的第二部分变形为向背离电池单体内部方向凸出的形状，此时薄弱部受到第一部分和/或第二部分的拉伸，促进薄弱部的开裂，实现快速泄压，更加有效地避免电池发生爆炸。
在一些实施例中，所述第一部分的厚度大于或等于所述第二部分的厚度。由于第二部分相对较薄而第一部分相对较厚，当电池单体内部气压或温度进一步增加到大于或等于第一预定值时，第二部分更容易、更迅速地变为向背离电池单体内部方向凸出的形状，并产生较大的变形，而第一部分则产生较小的变形，从而对薄弱部进行更有效的拉伸，促进薄弱部的开裂，实现快速泄压，避免电池发生爆炸。
在一些实施例中，当所述电池单体内部温度或气压大于或等于第二预定值时，所述薄弱部致动而使得所述电池单体内部压力通过所述泄压机构泄放。即，第二预定值是泄压机构的爆破压力或温度，当电池单体内部温度或气压大于或等于第二预定值时，薄弱部致动实现泄压功能。
在一些实施例中，所述第二部分还包括中间区域，所述中间区域与所述外边缘区域连接，并且所述中间区域基本平行于设置所述泄压机构的所述壳体板的部位。
由于中间区域基本平行于所述端盖，因此第二部分不会发生过于剧烈 的变形，从而不容易在第二部分发生开裂，能够降低从薄弱部以外的位置致动的风险。
在一些实施例中，所述第二部分设置有薄壁区。
设置薄壁区能够使第二部分更容易在气压的作用下发生变形。当泄压机构的尺寸较小，不容易将第二部分整体做得足够薄时，设置薄壁区能够容易地实现第二部分的变形，促进薄弱部致动。
在一些实施例中，在所述第一部分设置有加强结构。
设置加强结构能够提高第一部分的强度，增强对薄弱部的支撑，防止第一部分发生不必要的变形，保证在较小的气压或温度下第一部分有效地对薄弱部进行挤压，抑制薄弱部的开裂，防止泄压机构在电池单体在正常工作致动，有效延长泄压机构的寿命。
在一些实施例中，所述加强结构包括设置在所述第一部分一侧表面的凸起的加强筋。
该加强筋可以增加第一部分的部分区域的厚度，提高第一部分的强度。
在一些实施例中，所述加强结构还包括设置在所述第一部分的另一侧表面、在与所述加强筋对应的位置的凹部。
该凹部可以提高第一部分的强度，而且该加强筋和凹部可以通过冲压成形，易于制造。
在一些实施例中，所述连接部为环形，包括两个直线部和分别与两个所述直线部的端部连接的两个弧形部，所述加强结构位于与所述直线部对应的所述第一部分上。
由于直线部处的第一部分的稳定性比弧形部差，因此，将加强结构设置在与直线部对应的位置上，能够更有效地提高第一部分的强度。
即，泄压机构的轮廓为跑道形状，这可以实现较大的排气面积，有利于泄压。
在一些实施例中，所述薄弱部的至少部分区域的厚度小于所述第一部分和第二部分的厚度。即，薄弱部的一部分的厚度没有减薄，因此当薄弱部 破裂时，第二部分不会随气流等排放物飞出。
在一些实施例中，所述薄弱部为凹槽。凹槽结构可以通过冲压成形，易于制造。
第二方面，本申请提供了一种电池单体，包括第一方面的泄压机构。
第三方面，本申请提供了一种电池，包括：第二方面的电池单体。
第四方面，本申请提供了一种用电装置，包括：第三方面的电池，该电池用于提供电能。
第五方面，提供了一种泄压机构制造方法，包括：提供连接部，将其设置于所述泄压机构外周边区域，用于与所述壳体板连接；提供第一部分，将其一端与所述连接部连接，另一端向电池单体内部方向倾斜伸出；提供薄弱部，将其连接于所述第一部分的所述伸出的一端；以及提供第二部分，使其具有向电池单体内部方向凸出的形状，使其外边缘区域与所述薄弱部连接；其中，当所述电池单体内部气压或温度小于第一预定值时，所述薄弱部受到所述第一部分和/或所述第二部分的挤压。
上述说明仅是本申请技术方案的概述，为了能够更清楚了解本申请的技术手段，而可依照说明书的内容予以实施，并且为了让本申请的上述和其它目的、特征和优点能够更明显易懂，以下特举本申请的具体实施方式。
附图说明
通过阅读对下文优选实施方式的详细描述，各种其他的优点和益处对于本领域普通技术人员将变得清楚明了。附图仅用于示出优选实施方式的目的，而并不认为是对本申请的限制。而且在全部附图中，用相同的附图标号表示相同的部件。在附图中：
图1为本申请一些实施例的车辆的结构示意图；
图2为本申请一些实施例的电池的结构示意图；
图3为本申请一些实施例的电池单体的爆炸图；
图4为本申请一些实施例的端盖的主视图；
图5为图4的a-a剖视图；
图6为本申请一些实施例的泄压机构的立体图；
图7为图6的泄压机构的视图；
图8为图7的b-b剖视图；
图9为图8中区域X1的放大图；
图10为泄压机构在电池单体内部气压或温度小于第一预定值时的立体图；
图11为泄压机构的剖视图；
图12为图11的区域X2的放大图；
图13为电池单体内部气压或温度升高至大于或等于第一预定值，第二部分变为向上凸出状态时的立体图；
图14为泄压机构的剖视图；
图15为图14的区域X3的放大图；
图16为电池单体内部气压或温度升高至大于或等于第二预定值，泄压机构即将破裂时的立体图；
图17为泄压机构的剖视图；
图18为图17的区域X4的放大图。
图19为本申请一些实施例的泄压机构中与区域X1对应的部分的放大图，显示泄压机构的一个变形例；
图20为现有技术的泄压机构的初始状态；
图21为图20中区域X5的放大图；
图22为现有技术的泄压机构在较低气压下的状态；
图23为图22中区域X6的放大图；
图24显示现有技术中的泄压机构开裂的状态；
图25为图24的中区域X7的放大图；
图26为本申请另一实施例的泄压机构的局部放大图；
图27为本申请又一些实施例的泄压机构的立体图；
图28为图27的区域X9的放大图；
图29为图27的泄压机构另一方向上的立体图；
图30为图29的区域X10的放大图；
图31为图27的泄压机构在背离电池单体一侧的主视图；
图32为图31中的泄压机构的剖视图；
图33为图31中的泄压机构的另一剖视图；
图34本申请一些实施例的泄压机构的制造方法的示意性流程图；
具体实施方式中的附图标号如下：
电池单体1，
端盖10，壳体20，电极端子30，电极组件40，主体部41，极耳42，正极极耳421，负极极耳422，壳体板50，连接构件60；
泄压机构100，连接部101，第一部分102，薄弱部103，第二部分104；外边缘区域1041，中间区域1042，薄壁区1043；
加强结构1021，加强筋1021b，凹部1021a，局部加厚部1021c；直线部1011，弧形部1012；
比较例的泄压机构200，连接部201，第一部分202，薄弱部203，第二部分204；
控制器300，马达400，电池500；
箱体600，第一外壳601，第二外壳602；
车辆800。
具体实施方式
下面将结合附图对本申请技术方案的实施例进行详细的描述。以下实施例仅用于更加清楚地说明本申请的技术方案，因此只作为示例，而不能以此来限制本申请的保护范围。
除非另有定义，本申请所使用的所有的技术和科学术语与属于本申请的技术领域的技术人员通常理解的含义相同；本申请中在申请的说明书中所 使用的术语只是为了描述具体的实施例的目的，不是旨在于限制本申请；本申请的说明书和权利要求书及上述附图说明中的术语“包括”和“具有”以及它们的任何变形，意图在于覆盖不排他的包含。本申请的说明书和权利要求书或上述附图中的术语“第一”、“第二”等是用于区别不同对象，而不是用于描述特定顺序或主次关系。
在本申请中提及“实施例”意味着，结合实施例描述的特定特征、结构或特性可以包含在本申请的至少一个实施例中。在说明书中的各个位置出现该短语并不一定均是指相同的实施例，也不是与其它实施例互斥的独立的或备选的实施例。本领域技术人员显式地和隐式地理解的是，本申请所描述的实施例可以与其它实施例相结合。
在本申请的描述中，需要说明的是，除非另有明确的规定和限定，术语“安装”、“相连”、“连接”、“附接”应做广义理解，例如，可以是固定连接，也可以是可拆卸连接，或一体地连接；可以是直接相连，也可以通过中间媒介间接相连，可以是两个元件内部的连通。对于本领域的普通技术人员而言，可以根据具体情况理解上述术语在本申请中的具体含义。
本申请中术语“和/或”，仅仅是一种描述关联对象的关联关系，表示可以存在三种关系，例如，A和/或B，可以表示：单独存在A，同时存在A和B，单独存在B这三种情况。另外，本申请中字符“/”，一般表示前后关联对象是一种“或”的关系。
本申请中出现的“多个”指的是两个以上(包括两个)，同理，“多组”指的是两组以上(包括两组)，“多片”指的是两片以上(包括两片)。
本申请中，电池单体可以包括锂离子二次电池、锂离子一次电池、锂硫电池、钠锂离子电池、钠离子电池或镁离子电池等，本申请实施例对此并不限定。电池单体可呈圆柱体、扁平体、长方体或其它形状等，本申请实施例对此也不限定。电池单体一般按封装的方式分成三种：柱形电池单体、方体方形电池单体和软包电池单体，本申请实施例对此也不限定。
本申请的实施例所提到的电池是指包括一个或多个电池单体以提供更 高的电压和容量的单一的物理模块。例如，本申请中所提到的电池可以包括电池模块或电池包等。电池一般包括用于封装一个或多个电池单体的箱体。箱体可以避免液体或其他异物影响电池单体的充电或放电。
电池单体包括电极组件和电解液，电极组件由正极片、负极片和隔离膜组成。电池单体主要依靠金属离子在正极片和负极片之间移动来工作。正极片包括正极集流体和正极活性物质层，正极活性物质层涂覆于正极集流体的表面，未涂敷正极活性物质层的集流体凸出于已涂覆正极活性物质层的集流体，未涂敷正极活性物质层的集流体作为正极极耳。以锂离子电池为例，正极集流体的材料可以为铝，正极活性物质可以为钴酸锂、磷酸铁锂、三元锂或锰酸锂等。负极片包括负极集流体和负极活性物质层，负极活性物质层涂覆于负极集流体的表面，未涂敷负极活性物质层的集流体凸出于已涂覆负极活性物质层的集流体，未涂敷负极活性物质层的集流体作为负极极耳。负极集流体的材料可以为铜，负极活性物质可以为碳或硅等。为了保证通过大电流而不发生熔断，正极极耳的数量为多个且层叠在一起，负极极耳的数量为多个且层叠在一起。隔离膜的材质可以为PP或PE等。此外，电极组件可以是卷绕式结构，也可以是叠片式结构，本申请实施例并不限于此。
电池技术的发展要同时考虑多方面的设计因素，例如，能量密度、循环寿命、放电容量、充放电倍率等性能参数，另外，还需要考虑电池的安全性。
对于电池单体来说，主要的安全危险来自于充电和放电过程，同时还有适宜的环境温度设计，为了有效地避免不必要的损失，对电池单体一般会有至少三重保护措施。具体而言，保护措施至少包括开关元件、选择适当的隔离膜材料以及泄压机构。开关元件是指电池单体内的温度或者电阻达到一定阈值时而使电池停止充电或者放电的元件。隔离膜用于隔离正极片和负极片，可以在温度上升到一定数值时自动溶解掉附着在其上的微米级(甚至纳米级)微孔，从而使金属离子不能在隔离膜上通过，终止电池单体的内部反应。
泄压机构是指电池单体的内部压力或温度达到预定阈值时致动以泄放内部压力或温度的元件或部件。该阈值的数值根据设计需求不同而不同，取决于电池单体中的正极极片、负极极片、电解液和隔离膜中一种或几种的材料。泄压机构可以采用诸如防爆阀、气阀、泄压阀或安全阀等的形式，具体可以采用压敏或温敏的元件或构造。当电池单体的内部压力或温度达到预定阈值时，泄压机构执行动作或者泄压机构中设有的薄弱结构被破坏开裂，从而形成可供内部压力或温度泄放的开口或通道。
本申请中所提到的“致动”是指泄压机构产生动作或被激活至一定的状态，从而使得电池单体的内部压力及温度得以被泄放。泄压机构产生的动作可以包括但不限于：泄压机构中的至少一部分破裂、破碎、被撕裂或者打开，等等。泄压机构在致动时，电池单体的内部的高温高压物质作为排放物会从致动的部位向外排出。以此方式能够在可控压力或温度的情况下使电池单体发生泄压及泄温，从而避免潜在的更严重的事故发生。
本申请中所提到的来自电池单体的排放物包括但不限于：电解液、被溶解或分裂的正负极极片、隔离膜的碎片、反应产生的高温高压气体、火焰，等等。
电池单体上的泄压机构对电池的安全性有着重要影响。例如，当发生短路、过充等现象时，可能会导致电池单体内部发生热失控从而压力或温度骤升。这种情况下通过泄压机构致动可以将内部压力及温度向外释放，以防止电池单体爆炸、起火。
在电池单体正常工作时，电池单体内部也会有一定的气压施加到泄压机构上，虽然该气压低于设计的初始致动气压的下限，但是在气压的持续作用以及电池单体内部温度作用下，泄压机构的晶界发生滑移，晶粒沿晶界扩散，最终使泄压机构在结构上变薄，导致泄压机构的压力承受能力降低，就有可能导致泄压机构在小于设定的致动压力作用下发生破裂而失效。
鉴于此，本申请提供一种泄压机构，该泄压机构包括一端向电池单体内部方向倾斜伸出的第一部分，和具有向电池单体内部方向凸出的形状的第 二部分。在电池单体内部的气压及温度的作用下，第二部分向背离电池单体内部方向移动，而第一部分受到连接部的约束，有向背离电池单体内部方向移动的趋势。因此，当电池单体内部的气压或温度较小时，具体而言，小于第一预定值时，泄压机构的电池单体内部一侧的轮廓存在周长减小、向泄压机构中心收缩的趋势，使薄弱部受到第一部分和/或第二部分的挤压，抑制薄弱部的开裂，防止泄压机构在气压较小的情况下开裂，有效延长泄压机构的寿命。
这里，将第一预定值定义为第一部分和/或第二部分从挤压薄弱部的状态变为拉伸薄弱部状态的气压或温度值。
本申请实施例描述的技术方案均适用于各种使用电池的装置，例如，手机、便携式设备、笔记本电脑、电瓶车、电动玩具、电动工具、电动车辆、船舶和航天器等，例如，航天器包括飞机、火箭、航天飞机和宇宙飞船等。
应理解，本申请实施例描述的技术方案不仅仅局限适用于上述所描述的设备，还可以适用于所有使用电池的设备。但为描述简洁，下述实施例均以电动车辆为例进行说明。
接下来，对本申请的具体实施例进行详细说明。
图1为本申请一个实施例的车辆800的结构示意图。车辆800可以为燃油汽车、燃气汽车或新能源汽车，新能源汽车可以是纯电动汽车、混合动力汽车或增程式汽车等。车辆的内部可以设置马达400，控制器300以及电池500，控制器300用来控制电池500为马达400的供电。例如，在车辆的底部或车头或车尾可以设置电池500。电池500可以用于车辆的供电，例如，电池500可以作为车辆的操作电源，用于车辆800的电路系统，例如，用于车辆800的启动、导航和运行时的工作用电需求。在本申请的另一实施例中，电池500不仅仅可以作为车辆800的操作电源，还可以作为车辆800的驱动电源，替代或部分地替代燃油或天然气为车辆800提供驱动动力。
为了满足不同的使用电力需求，电池可以包括多个电池单体，其中，多个电池单体之间可以串联或并联或混联，混联是指串联和并联的混合。电 池也可以称为电池包。可选地，多个电池单体可以先串联或并联或混联组成电池模块，多个电池模块再串联或并联或混联组成电池。也就是说，多个电池单体可以直接组成电池，也可以先组成电池模块，电池模块再组成电池。
图2为本申请一个实施例的电池500的结构示意图。电池500可以包括多个电池单体1。电池500还可以包括箱体600(或称罩体)，箱体600为中空结构，多个电池单体1容纳于箱体600内。如图2所示，箱体600可以包括第一外壳601和第二外壳602，第一外壳601和第二外壳602扣合在一起。第一外壳601和第二外壳602的形状可以根据多个电池单体1组合的形状而定，第一外壳601和第二外壳602均具有一个开口。例如，第一外壳601和第二外壳602均可以为中空长方体且各自的一个面为开口面，第一外壳601的开口和第二外壳602的开口相对设置，并且第一外壳601和第二外壳602相互扣合形成具有封闭腔室的箱体。多个电池单体1相互并联或串联或混联组合后置于第一外壳601和第二外壳602扣合后形成的箱体内。
根据不同的电力需求，电池单体1的数量可以设置为任意数值。多个电池单体1可通过串联、并联或混联的方式连接以实现较大的容量或功率。由于每个电池500中包括的电池单体1的数量可能较多，为了便于安装，可以将电池单体1分组设置，每组电池单体1组成电池模块。电池模块中包括的电池单体1的数量不限，可以根据需求设置。例如，电池可以包括多个电池模块,这些电池模块可通过串联、并联或混联的方式进行连接。
图3为本申请一些实施例的电池单体1的爆炸图。图4为本申请一些实施例的端盖10的俯视图。图5为图4中直线a-a处的、沿箭头A方向的剖视图。
如图3所示，电池单体1包括壳体板50以及设置于壳体板50内的电极组件40，壳体板50包括端盖10和壳体20，壳体20具有开口，电极组件40经由壳体20的开口设置于壳体20中。电极组件40包括主体部41和极耳42，极耳42从主体部41延伸。主体部41包括正极极片、负极极片和隔离膜。主体部41可以是由正极极片、隔离膜和负极极片通过卷绕形成的卷绕式结构， 也可以是由正极极片、隔离膜和负极极片通过层叠布置形成的层叠式结构。正极极耳421和负极极耳422可以位于主体部41的同一侧，也可以分别位于主体部41相对的两侧。在图3中，示例性的示出了正极极耳421和负极极耳422位于主体部41的同一侧的情况。端盖10覆盖壳体20的开口，形成用于容纳电极组件40和电解质的密闭空间，电解质可以是电解液。
如图3、图4、图5所示，作为一些实施例，泄压机构100设置在端盖10的大致中间部位，但是根据电极组件设置方式和位置的不同，泄压机构100也可以设置在壳体板50的其它位置。端盖10上还设置有两个电极端子30，电极端子30用于与极耳42电连接，用于输出电池单体1的电能，或者用于连接外部电源给电池单体充电。泄压机构100位于两个电极端子30之间。电池单体1还包括连接构件60，电极端子30与极耳42通过连接构件60电连接。
图6为本申请一些实施例的泄压机构100的立体图。图7为泄压机构100的朝向电池单体内部一侧的视图。图8为图7中直线b-b处的、沿箭头B方向的剖视图。图9为图8中区域X1的放大图。
图6至图9显示的是泄压机构100的初始状态，即未施加压力的状态。
如图6至图9所示，泄压机构100包括连接部101、第一部分102、薄弱部103和第二部分104。连接部101位于泄压机构100的外周边区域，用于与图3、图4、图5中的端盖10连接。作为一个实施例，比如，如图7所示，连接部101包括两个直线部1011和分别与两个直线部1011的端部连接的两个弧形部1012，整体呈跑道状。
如图9所示，第一部分102的一端与连接部101连接，另一端向电池单体1内部的电极组件40的方向，即图3中向下的方向倾斜伸出。薄弱部103连接于第一部分102的该伸出的一端。如图6、图8所示，第二部分104具有向电池单体1内部方向凸出的形状，第二部分104的外边缘区域1041与薄弱部103连接。当电池单体1内部气压或温度小于第一预定值时，薄弱部103受到第一部分102和/或第二部分104的挤压。
如图9所示，第一部分102整体比连接部101更靠近电池单体1内部。 第一部分102伸出部分的形状没有特殊限制，在本实施例中，如图9所示，第一部分102大致沿直线方向电池单体1内部伸出，但第一部分102也可以是以弧形、曲线形状伸出。
薄弱部103位于第一部分102和第二部分104之间，即位于第一部分102的伸出的一端，比第一部分102更靠近电池单体1内部。薄弱部103的强度小于第一部分102和第二部分104，在泄压时薄弱部103处致动泄压。
如图6、图7、图8所示，第二部分104为泄压机构100中面积最大的部分，位于泄压机构100的中部，包括外边缘区域1041和中间区域1042(见图8)，外边缘区域1041一端与薄弱部103连接，另一端与中间区域1042连接。第二部分104整体比薄弱部103更靠近电池单体1内部，且具有向电池单体1内部方向凸出的形状，比如，第二部分104为向电池单体1内部方向凸出的拱形，但也可以是不规则的凸出形状。如图8所示，第二部分104的外边缘区域1041向电池单体内部方向倾斜延伸，延伸方向与第一部分102伸出的方向大致相同，中间区域1042大致平行于设置泄压机构100的端盖10。
由于中间区域1042基本平行于端盖10，因此第二部分104不会发生过于剧烈的变形，从而不容易在第二部分104发生开裂，能够降低从薄弱部103以外的位置致动的风险。
图10至图18显示本申请的实施例的泄压机构100在不同气压或温度下的状态。
图10为泄压机构100在电池单体1内部气压或温度小于第一预定值时的立体图。图11为泄压机构100的剖视图，切剖位置和观察视角与图8相同，参见图8中的说明。图12为图11中区域X2的放大图。
在电池单体1正常工作时，电池单体1内部气压或温度较低。以下以气压为例说明。电池单体1内部的气压持续作用于泄压机构100，使得第一部分102、薄弱部103和第二部分104发生向上的移动或有向上移动的趋势，第一部分102、薄弱部103和第二部分104作为整体，轮廓周长减小、向中心收缩。
具体如图11、图12所示，由于第一部分102向电池单体1的内部倾斜，使得薄弱部103的位置相比于连接部101更靠近电池单体的内部，也就是薄弱部103的位置比泄压机构100与端盖10的固定点的位置更靠近电池单体的内部。并且，由于第一部分102的一端受到连接部101的约束，第一部分102的伸向电池单体1内部的一端沿图12中右侧箭头方向挤压薄弱部103，从而抑制薄弱部103的开裂，防止泄压机构100在电池单体1正常工作时蠕变失效，有效延长泄压机构的寿命。同样，如图12所示，第二部分104在气压作用下向上方移动，第二部分104沿图12中左侧箭头方向挤压薄弱部103，抑制薄弱部103的开裂，防止泄压机构100在电池单体1正常工作时蠕变失效，有效延长泄压机构100的寿命。
图13显示电池单体1内部气压或温度升高至大于或等于第一预定值，第二部分104变为向上翻转而凸出的过程状态图。图14为泄压机构100的剖视图，切剖位置和观察视角与图8、图11相同。图15为图14中区域X3的放大图。
如图13至图15所示，当电池单体1内部气压或温度上升，达到或超过第一预定值时，第一部分102、薄弱部103和第二部分104整体继续向上移动，其中第二部分104发生较大的变形，从向下凸出的形状向上翻转，变为向上凸出的形状。此时，第二部分104的中间区域1042移动到薄弱部103的上方，第一部分102受连接部101约束，移动很小。第二部分104翻转完成之后，第二部分104整体移动到薄弱部103上方，第二部分104从图12所示的挤压薄弱部103的状态变为拉伸薄弱部103的状态，促进薄弱部103开裂、有助于实现快速泄压。
这里，定义第二预定值时表示泄压机构100的预定泄压温度或压力值。即，当电池单体1内部的温度或压力值达到第二预定值时，泄压机构100致动、比如，薄弱部103开裂，电池单体1内部压力通过泄压机构100泄放。
图16为电池单体1内部气压或温度升高至大于或等于第二预定值，泄压机构100即将破裂时的立体图。图17为泄压机构100的剖视图，切剖位置 和观察视角与图8、图11、图14相同。图18为图17中区域X4的放大图。
如图16至图18所示，当电池单体1内部气压或温度到达第二预定值时，第一部分102、薄弱部103和第二部分104整体继续向上移动，对薄弱部103施加更大的拉伸力。第一部分102受到连接部101的约束，移动很小，因此形成第二部分104和第一部分102对薄弱部103的有效拉伸，导致薄弱部103破裂，释放电池单体1内部的压力。
图19显示图9中的泄压机构100的一个变形例。
如图19所示，在一些实施例中，第一部分102的厚度大于或等于第二部分104的厚度。
由于第二部分104相对较薄而第一部分102相对较厚，当电池单体1内部气压或温度增加时，较薄的第二部分104更容易、更迅速地变为向背离电池单体1内部方向凸出的形状，并产生较大的变形，而较厚的第一部分102产生较小的变形，因此第一部分102、第二部分104对薄弱部103形成较好的拉伸，促进薄弱部103开裂，实现快速泄压，有效地防止电池发生爆炸。
作为比较例，以下说明现有技术的泄压机构。
图20为现有技术的泄压机构的剖视图，切剖位置和观察视角与图8相同。图21为图20中区域X5的放大图。
图20至图21显示的是泄压机构200的初始状态，即未施加压力的状态。
图20、图21所示的现有技术的泄压机构200包括连接部201、第一部分202、薄弱部203和第二部分204。泄压机构200的轮廓形状设置成与本申请的泄压机构100大致相同。如图20所示，第一部分202、第二部分204与连接部201位于同一平面，泄压机构200的第一部分202没有向电池单体内部伸出，第二部分204不具有向电池单体1内部方向凸出的形状。
图22显示现有技术的泄压机构200在较低气压下作用下的状态(切剖位置和观察视角与图20相同)。图23为图22中区域X6的放大图。
泄压机构200在电池单体正常工作时受电池单体内部气压作用，此时， 第一部分202和第二部分204向远离电池单体内部的方向发生移动，在电池单体内部气压的持续作用下，第一部分202和第二部分204分别沿图23中箭头方向对薄弱部203进行持续的拉伸，因此薄弱部203在电池单体正常工作时、在较小气压作用下就有可能开裂。
图24显示现有技术中的泄压机构开裂的状态(切剖位置和观察视角与图20相同)。图25为图24的中区域X7的放大图。
泄压机构200长时间受到电池单体内部气压作用，由于薄弱部203持续受到第一部分202和第二部分204的拉伸而产生蠕变，使第一部分202和第二部分204继续向上方移动，导致薄弱部203在电池单体正常工作的状态下就发生破裂，发生蠕变失效。
图26为本申请其他实施例的泄压机构的剖视图的局部放大图(切剖位置和观察视角与图8相同)。
如图26所示，在第二部分104设置有薄壁区1043，该薄壁区1043的厚度小于第二部分104中其它区域的厚度。在一些实施例中，薄壁区1043为向电池单体1内部方向开口的环形凹槽。
当泄压机构100尺寸较小时，需要将第二部分104设置得足够薄，才能保证第二部分104在气压或温度大于或等于第一预定值时变为向背离电池单体1内部方向凸出的状态，以促进薄弱部103的开裂，实现与大尺寸的泄压机构相同的泄压效果。但是，受到制造设备和制造工艺的限制，很难将第二部分104作得足够薄。为此，可以在第二部分104设置薄壁区1043，在气压作用下，与第二部分104的其它区域相比，薄壁区1043更容易发生变形，使得第二部分104容易变为向背离电池单体1内部方向凸出的状态。
本申请的薄壁区1043不限于上述结构，也可以是向背离电池单体1内部方向开口的环形凹槽，也可以在第二部分104的上表面和下表面都设置环形凹槽。此外，薄壁区1043形状没有特别限制，也可以不是环形，而是弧形、直线形或者其它形状，为保证均匀承受气压，优选在第二部分104上对称设置薄壁区1043。此外，薄壁区1043的数量也没有特别限制，可根据需要适当 设置。
图27为本申请其他实施例的泄压机构100的背离电池单体1内部方向一侧的视图。图28为图27的区域X9的放大图。
图29为图27的泄压机构100的另一侧的立体图。图30为图29的区域X10的放大图。
图31为图27的泄压机构100在背离电池单体1内部方向一侧的平面图。图32为图31中的泄压机构100的剖视图(切剖位置和观察视角与图8相同)。图33为图31中的泄压机构100的直线l-l处的，沿箭头L方向的剖视图。
在一些实施例中，如图27至图30所示，在第一部分102设置有加强结构1021。
对于尺寸较大的泄压机构，因为泄压机构100的面积较大，气压的压力较大，即使在气压较低时第一部分102也会发生较大移动，无法有效地挤压薄弱部103。如果增加第一部分102的厚度来防止其不必要的变形，则第一部分与设计的薄弱部103的厚度差过大，难以形成所需厚度的薄弱部103，导致制造成本的提高。为此，通过设置加强结构1021，能够加强第一部分102的强度，又易于加工。
在一些实施例中，如图33所示，在第一部分102一侧表面设置有凸起的加强筋1021b。加强筋1021b可以设置在第一部分102的背离电池单体1内部方向一侧，也可以设置在第一部分102的朝向电池单体1内部方向一侧。
在一些实施例中，在第一部分102的另一侧表面、在与加强筋1021b对应的位置设置有凹部1021a，具体如图33所示，加强筋1021b和凹部1021a构成加强结构1021。在本实施例中，凹部1021a凹陷的深度大于加强筋1021b凸出的高度，凹部1021a开口的宽度(图33中左右方向)小于加强筋1021b的宽度。因此，在凹部1021a的左右两侧形成两个局部加厚的区域1021c，该局部加厚区域1021c的厚度大于第一部分102中其它位置的厚度。这样的结构未增加第一部分102整体的体积，却能提高第一部分102在主要受力方向 上的强度。而且，这样结构的加强结构1021可以通过冲压成形，易于制造。
除以上结构外，加强结构1021也可以是将第一部分102部分区域进行化学处理而使强度增加的结构。
在一些实施例中，如图27、29、31，连接部101为环形的板状结构，可通过例如焊接方式连接至端盖10。焊接的位置可以在端盖10的外侧；当第一部分102延伸超过端盖厚度时，焊接的位置也可以在端盖10的内侧。连接部101包括两个直线部1011和分别与两个直线部1011的端部连接的两个弧形部1012，上述加强结构1021位于与直线部1011对应的第一部分102上。由于直线部1011处的第一部分102的稳定性比弧形部1012处的第一部分102差，因此，将加强结构1021设置在与直线部1011对应的位置上，能够更有效地提高第一部分102的强度。当然，根据需要，将强结构1021也可以设置在与弧形部1012对应的位置上。两个直线部1011彼此大致平行，两个直线部1011和两个弧形部1012构成的连接部101整体呈环形跑道形状。
与常见的圆形形状的防爆片相比，本实施例的连接部101呈环形跑道状，在将泄压机构100应用于小尺寸的电池单体时，对于相同的长宽区域，泄压时的排气面积更大，能够更快地排出气体。
在一些实施例中，泄压机构100在端盖10上的设置方式为，如图4所示，泄压机构100位于两个电极端子30之间，与直线部相比，两个弧形部分别靠近泄压机构100两侧的电极端子30，更具体地，两个弧形部1012的弧形中点的连线与两个电极端子30的连线在同一条直线上。例如，两个弧形部1012的弧形中点的连线与两个电极端子30的连线都在图4所示的a-a剖线上。这样，与其它的设置方向相比，泄压机构100受应力作用发生的形变最大。当然，泄压机构100也可以如图3所示的那样，设置成直线部更靠近电极端子30的方式。
在一些实施例中，薄弱部103的至少部分区域的厚度小于第一部分102和第二部分104的厚度，即，并非薄弱部103所有部分的厚度都小于第一部分102和第二部分104的厚度，只是薄弱部103的一部分的厚度小于第一部 分102和第二部分104的厚度，其他部分的厚度可以等于甚至大于第一部分102和/或第二部分104的厚度。
由于薄弱部103一部分的厚度没有减小，所以当薄弱部103破裂时，第二部分104不会随气流等排放物飞出。
在一些实施例中，薄弱部103为凹槽结构，比如，是向电池单体1内部的一侧开口的环形凹槽结构。而且，该环形凹槽结构可以包括多个断续的凹槽，即，满足薄弱部103的部分区域的厚度小于第一部分102和第二部分104的厚度。
由于薄弱部103为凹槽结构，薄弱部103的厚度和强度小于第一部分102以及第二部分104，所以薄弱部103容易开裂。
但薄弱部103不限于凹槽结构，只要薄弱部103的强度足够小于第一部分102和第二部分104的结构即可。例如，薄弱部103也可以是通过化学处理使得薄弱部103软化而强度下降的结构。
以上，对本申请实施例的泄压机构100进行了说明。
本申请另一方面，还提供一种电池500，包括上述的电池单体1。
本申请的又一方面，还提供一种用电装置，包括上述的电池500，其用于提供电能。可选地，用电装置可以为图1所示的车辆800，也可以是船舶或航天器。
本申请还提供了一种泄压机构的制造方法。
图34示出本申请一个实施例的泄压机构100的制造方法的流程图。
如图34所示，本实施例的制造方法包括：
步骤S1，提供连接部101，将其设置于泄压机构100外周边区域，用于与端盖10连接；
步骤S2，提供第一部分102，将其一端与连接部连接101，另一端向电池单体内部方向倾斜伸出；
步骤S3，提供薄弱部103，将其连接于第一部分102的上述伸出的一端；以及
步骤S4，提供第二部分104，使其具有向电池单体内部方向凸出的形状，使其外边缘区域与薄弱部103连接；其中，当电池单体内部气压或温度小于第一预定值时，薄弱部103受到第一部分102和/或第二部分104的挤压。
更具体而言，使用金属材料将上述连接部101、第一部分102及第二部分104经由模具一体成形。金属材料例如为铝箔、铜箔等。此时，第一部分102及第二部分104在外形上并没有区分开。在第一部分102及第二部分104的整体上通过冲压或切削等方式在预先设计的位置上形成凹槽状的薄弱部103，得到如图6至10所示的泄压机构100。通过选用适当的材料、设定第一部分102的厚度、第一部分102伸出的长度、第二部分104的面积、第二部分104的厚度、薄弱部103的厚度等等参数，可以实现在电池单体内部气压或温度小于第一预定值时薄弱部103受到第一部分102、第二部分104的挤压的效果。具体参数的设计根据泄压机构的尺寸等适当设定，本申请在此不做赘述。
在一个优选的实施例中，设置第一部分102的厚度大于或等于所述第二部分104的厚度。比如，这可以通过对成形模具进行形状的调整来实现。
在一个优选的实施例中，在第二部分104设置有如图26所示的薄壁区1043，以利于第二部分104的变形。薄壁区1043可通过对第二部分104进行冲压或切削等方式形成，也可以通过设置模具的形状与第二部分104一体成形。
在一个优选的实施例中，在第一部分102设置有如图27至32所示的加强结构1021，以对薄弱区103进行支撑。加强结构1021通过对第一部分102进行冲压的方式形成，也可以通过设置模具的形状与第一部分102一体成形。
最后应说明的是：以上各实施例仅用以说明本申请的技术方案，而非对其限制；尽管参照前述各实施例对本申请进行了详细的说明，本领域的普通技术人员应当理解：其依然可以对前述各实施例所记载的技术方案进行修改，或者对其中部分或者全部技术特征进行等同替换；而这些修改或者替换， 并不使相应技术方案的本质脱离本申请各实施例技术方案的范围，其均应涵盖在本申请的权利要求和说明书的范围当中。尤其是，只要不存在结构冲突，各个实施例中所提到的各项技术特征均可以任意方式组合起来。本申请并不局限于文中公开的特定实施例，而是包括落入权利要求的范围内的所有技术方案。

Claims (19)

  1. 一种泄压机构，设置于电池单体的壳体板，包括：
    连接部，其位于所述泄压机构外周边区域，用于与所述壳体板连接；
    第一部分，其一端与所述连接部连接，另一端向电池单体内部方向倾斜伸出；
    薄弱部，其连接于所述第一部分的所述伸出的一端；以及
    第二部分，其具有向电池单体内部方向凸出的形状，其外边缘区域与所述薄弱部连接，
    其中，当所述电池单体内部温度或气压小于第一预定值时，所述薄弱部受到所述第一部分和/或所述第二部分的挤压。
  2. 根据权利要求1所述的泄压机构，其中，
    当电池单体内部温度或气压大于或等于所述第一预定值时，所述第二部分从向电池单体内部方向凸出的形状变为向背离电池单体内部方向凸出的形状，所述薄弱部受到所述第二部分和/或所述第一部分的拉伸。
  3. 根据权利要求1或2所述的泄压机构，其中，所述第一部分的厚度大于或等于所述第二部分的厚度。
  4. 根据权利要求1-3任一项所述的泄压机构，其中，当所述电池单体内部温度或气压大于或等于第二预定值时，所述薄弱部致动而使得所述电池单体内部压力通过所述泄压机构泄放。
  5. 根据权利要求1-4任一项所述的泄压机构，其中，所述第二部分还包 括中间区域，所述中间区域与所述外边缘区域连接，并且所述中间区域基本平行于设置所述泄压机构的所述壳体板的部位。
  6. 根据权利要求1-5任一项所述的泄压机构，其中，所述第二部分设置有薄壁区。
  7. 根据权利要求1-6任一项所述的泄压机构，其中，在所述第一部分设置有加强结构。
  8. 根据权利要求7所述的泄压机构，其中，所述加强结构包括设置在所述第一部分一侧表面的凸起的加强筋。
  9. 根据权利要求8所述的泄压机构，其中，所述加强结构还包括设置在所述第一部分的另一侧表面、在与所述加强筋对应的位置的凹部。
  10. 根据权利要求8或9所述的泄压机构，其中，所述连接部为环形，包括两个直线部和分别连接两个所述直线部的端部的两个弧形部，所述加强结构位于与所述直线部对应的所述第一部分上。
  11. 根据权利要求1-10任一项所述的泄压机构，其中，所述薄弱部的至少部分区域的厚度小于所述第一部分和第二部分的厚度。
  12. 根据权利要求1-11任一项所述的泄压机构，其中，所述薄弱部为凹槽。
  13. 一种电池单体，其中，包括根据权利要求1-12任一项所述的泄压机构。
  14. 一种电池，其中，包括根据权利要求13所述的电池单体。
  15. 一种用电装置，其中，包括：根据权利要求14所述的电池，所述电池用于提供电能。
  16. 一种泄压机构制造方法，其特征在于，包括：
    提供连接部，将其设置于所述泄压机构外周边区域，用于与所述壳体板连接；
    提供第一部分，将其一端与所述连接部连接，另一端向电池单体内部方向倾斜伸出；
    提供薄弱部，将其连接于所述第一部分的所述伸出的一端；以及
    提供第二部分，使其具有向电池单体内部方向凸出的形状，使其外边缘区域与所述薄弱部连接；
    其中，
    其中当所述电池单体内部温度或气压小于第一预定值时，所述薄弱部受到所述第一部分和/或所述第二部分的挤压。
  17. 根据权利要求16所述的制造方法，其中，设置所述第一部分的厚度大于或等于所述第二部分的厚度。
  18. 根据权利要求16或17所述的制造方法，其中，在所述第二部分设置有薄壁区，以利于所述第二部分的变形。
  19. 根据权利要求16-18任一项所述的制造方法，其中，在所述第一部分设置有加强结构，以对所述薄弱区进行支撑。
PCT/CN2021/121962 2021-09-29 2021-09-29 泄压机构、电池单体、电池、用电装置及其制造方法 WO2023050236A1 (zh)

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