WO2024000246A1 - Élément de batterie, batterie et dispositif électrique - Google Patents

Élément de batterie, batterie et dispositif électrique Download PDF

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Publication number
WO2024000246A1
WO2024000246A1 PCT/CN2022/102287 CN2022102287W WO2024000246A1 WO 2024000246 A1 WO2024000246 A1 WO 2024000246A1 CN 2022102287 W CN2022102287 W CN 2022102287W WO 2024000246 A1 WO2024000246 A1 WO 2024000246A1
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WO
WIPO (PCT)
Prior art keywords
resistance
battery cell
battery
silicone oil
flame retardant
Prior art date
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PCT/CN2022/102287
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English (en)
Chinese (zh)
Inventor
张宇
赵延杰
李星
Original Assignee
宁德时代新能源科技股份有限公司
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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 CN202280046081.1A priority Critical patent/CN117642924A/zh
Priority to PCT/CN2022/102287 priority patent/WO2024000246A1/fr
Publication of WO2024000246A1 publication Critical patent/WO2024000246A1/fr

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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
    • H01M50/50—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
    • 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
    • H01M50/581—Devices or arrangements for the interruption of current in response to temperature
    • 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 battery technology, and in particular to a battery cell, a battery and an electrical device.
  • Lithium-ion batteries have the advantages of high energy density, high voltage, and long cycle life, but the safety issues of lithium-ion batteries are the key to the development of lithium-ion batteries.
  • the present application provides a battery cell, battery and electrical device that can alleviate safety problems caused by excessive circulation.
  • this application provides a battery cell, including:
  • the battery core assembly is located in the receiving cavity
  • the resistance-increasing component is located in the accommodation cavity and includes a sealing shell and a resistance-increasing agent.
  • the resistance-increasing agent is sealed in the sealing shell;
  • the sealed case can be opened under the expansion pressure generated by the expansion of the battery core assembly to release the resistance increasing agent.
  • a resistance-increasing member is provided in the casing of the battery cell, so that the battery cell expands due to a significant increase in the thickness of the battery core components inside the casing during the later stages of the cycle. This expansion causes the expansion of the battery cell.
  • Pressure can be applied to the resistance-increasing component to open the sealed housing of the resistance-increasing component, thereby releasing the resistance-increasing agent into the accommodation cavity.
  • the resistance-increasing agent further reaches the position of the pole piece of the battery assembly, causing the pole piece resistance increase, which in turn causes the battery cells to be unable to be used normally, so the safety of the battery cells can be ensured.
  • the resistance increasing agent includes at least one of silicone oil or tetrafluoroethylene emulsion.
  • silicone oil and tetrafluoroethylene emulsion have insulating properties. After being released into the accommodation cavity, they can increase the resistance of the electrolyte to ensure that the battery cells cannot be used normally.
  • Silicone oil and tetrafluoroethylene emulsion have good chemical stability, so they can It can be stored in a sealed case for a long time without qualitative change, which improves the reliability of the resistance-increasing effect of the resistance-increasing component.
  • the silicone oil includes dimethyl silicone oil, ethyl silicone oil, phenyl silicone oil, methyl hydrogenated silicone oil, methyl phenyl silicone oil, methyl chlorophenyl silicone oil, methyl ethoxy silicone oil, methyl trisilicon oil At least one of fluoropropyl silicone oil, methylvinyl silicone oil, methylhydroxy silicone oil, ethyl hydrogen-containing silicone oil, hydroxyl hydrogen-containing silicone oil, and cyanide-containing silicone oil.
  • silicone oil types all have excellent heat resistance and small surface tension, which can avoid being affected by the high temperature of the battery cells, and are easily mixed into the electrolyte, improving the reliability of the resistance-increasing effect of the resistance-increasing component.
  • the mass of the resistance-increasing agent is m
  • the capacity of the battery cell is x
  • m is 0.4 to 0.6 times of x.
  • the wall thickness of the sealed housing is determined based on the ratio of the rupture pressure value of the resistance-increasing component to the rupture coefficient of the resistance-increasing component. Through the ratio of the rupture pressure value of the resistance-increasing component to the rupture coefficient of the resistance-increasing component, the wall thickness of the sealed case can be determined, thereby ensuring that the sealed case can rupture and open in the later stages of the cycle, thus ensuring the safety of the battery cells.
  • the rupture pressure value is determined based on the sum of the pressure value of the resistance-increasing agent acting on the sealed shell along the direction of gravity and the pressure value of the expansion pressure acting on the sealed shell.
  • the rupture pressure value can be determined, thereby determining the wall thickness of the sealed shell to ensure installation
  • the sealed housing can rupture and open late in the cycle.
  • the battery cell further includes a battery cell assembly, the battery cell assembly is disposed in the receiving cavity, and the resistance increasing member is disposed between the inner wall of the housing and the battery cell assembly.
  • the housing includes an adjacent first side wall and a second side wall, and the area of the first side wall is greater than the area of the second side wall;
  • the resistance increasing component is disposed between the first side wall and the battery core component.
  • the resistance-increasing component By arranging the resistance-increasing component between the first side wall with a larger area and the battery core assembly, the resistance-increasing component can have a larger stress-bearing area, thereby actively responding to the pressure changes in the accommodation cavity, thereby improving the performance of the battery cells. Later in the cycle, the resistance-increasing element opens and releases the reliability of the resistance-increasing agent.
  • the battery cell further includes a plurality of battery cell assemblies, all of the battery cell assemblies are disposed in the receiving cavity, and the resistance increasing member is disposed between two adjacent battery cell assemblies.
  • the battery cell further includes an auxiliary component.
  • the auxiliary component is disposed in the accommodation cavity.
  • the sealed housing can move relative to the auxiliary component under the force generated by pressure changes in the accommodation cavity, so as to be opened by the auxiliary component.
  • the auxiliary component includes a sharp portion, which is disposed toward the sealing housing and capable of piercing the sealing housing.
  • the resistance-increasing component further includes a flame retardant
  • the flame retardant is provided in the sealed housing.
  • the flame retardant can be released by opening the sealed case in the later stages of the cycle, so that when there is abnormal gas production inside the battery cell, the flame retardant can be promptly sprinkled on the surface of the cell assembly, thereby preventing and It has the dual function of extinguishing fire, thereby reducing the risk of combustion.
  • the flame retardant includes at least one of an organic liquid flame retardant or an inorganic liquid flame retardant.
  • Liquid flame retardants are liquid at room temperature and can vaporize at high temperatures, evaporating a large amount of fire heat and having a good cooling effect.
  • the flame retardant includes perfluorohexanone flame retardant, alkyl phosphate flame retardant, heptafluoropropane flame retardant, phosphorus nitrogen flame retardant, nitrogen flame retardant or silicon flame retardant. of at least one.
  • the flame retardant includes at least one of perfluorohexanone flame retardant, alkyl phosphate flame retardant, heptafluoropropane flame retardant, phosphorus nitrogen flame retardant, nitrogen flame retardant or silicon flame retardant. , can quickly vaporize at high temperatures and improve the rapidity of cooling.
  • the resistance-increasing component further includes a dispersant, and the dispersant is disposed in the sealed housing.
  • the dispersant and the resistance-increasing agent can be released simultaneously by opening the sealing shell at the later stage of the cycle, so that the resistance-increasing agent can be quickly and evenly dispersed into the accommodation cavity under the action of the dispersant, especially for extremely between the pole pieces, and even on the surface of the particles, thereby quickly and reliably increasing the resistance of the pole pieces to ensure the safety of the battery cells.
  • the dispersant includes at least one of polyoxyethylene sorbitan monooleate or montmorillonite.
  • Polyoxyethylene sorbitan monooleate or montmorillonite can be evenly mixed with the resistance increasing agent, and then be quickly and evenly dispersed after release.
  • the sealed housing is configured to melt and rupture when the external temperature reaches a preset temperature.
  • the sealed case By configuring the sealed case to melt and rupture when reaching a preset temperature to release the resistance-increasing agent, the battery cell can not only increase resistance in the later stages of the cycle, but also increase resistance under thermal runaway conditions, thus having a dual role. This greatly improves the safety of battery cells.
  • the sealed shell includes one of a polyvinyl chloride shell, a polyvinyl alcohol shell, a rubber shell, a cast polypropylene film shell, and a polyethylene terephthalate shell.
  • the melting points of polyvinyl chloride shells, polyvinyl alcohol shells and rubber shells are all greater than 150 degrees, and do not react with electrolytes, resistance increasing agents, flame retardants and dispersants, and can stably accommodate resistance increasing agents, Flame retardants and dispersants.
  • the present application provides a battery, including the battery cell in any of the above embodiments.
  • the battery cell expands due to a significant increase in the thickness of the battery core components inside the casing during the later stages of the cycle. This expansion causes the expansion of the battery cell.
  • Pressure can be exerted on the resistance-increasing component to open the sealed housing of the resistance-increasing component, thereby releasing the resistance-increasing agent into the accommodation cavity.
  • the resistance-increasing agent further reaches the position of the pole piece of the battery assembly, causing the pole piece resistance increase, which will cause the battery cells to be unable to be used normally, so the safety of the battery cells can be ensured.
  • the present application provides an electrical device, including the battery in any of the above embodiments.
  • a resistance-increasing member is provided in the casing of the battery cell, so that the battery cell expands due to a significant increase in the thickness of the battery core components inside the casing during the later stages of the cycle. This expansion causes the expansion of the battery cell.
  • Pressure can be applied to the resistance-increasing component to open the sealed housing of the resistance-increasing component, thereby releasing the resistance-increasing agent into the accommodation cavity.
  • the resistance-increasing agent further reaches the position of the pole piece of the battery assembly, causing the pole piece resistance increase, which in turn causes the battery cells to be unable to be used normally, so the safety of the battery cells can be ensured.
  • Figure 1 is a schematic structural diagram of a vehicle provided by some embodiments of the present application.
  • Figure 2 is an exploded view of a battery provided by some embodiments of the present application.
  • Figure 3 is a schematic diagram of the exploded structure of a battery cell according to some embodiments of the present application.
  • Figure 4 is a schematic half-section structural diagram of a battery cell according to some embodiments of the present application.
  • Figure 5 is a partial structural diagram of a battery cell according to some embodiments of the present application.
  • Electrode terminal 211 case 22, cell assembly 23, tab 231, casing 24, receiving cavity 241, first side wall 242, second side wall 243, resistance increasing member 25, sealing case 251, Resistance increasing agent 252, dispersing agent 253.
  • 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 present application.
  • the appearances of this 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. Those skilled in the art understand, both explicitly and implicitly, that the embodiments described herein may be combined with other embodiments.
  • multiple refers to more than two (including two).
  • multiple groups refers to two or more groups (including two groups), and “multiple pieces” refers to It is more than two pieces (including two pieces).
  • lithium-ion batteries Compared with other types of batteries such as lead-acid and cadmium-nickel, lithium-ion batteries have the advantages of large specific capacity, high operating voltage, fast charging speed, wide operating temperature range, long cycle life, small size, and light weight. It is widely used not only in portable electronic devices such as mobile phones, digital cameras and laptop computers, but also in large and medium-sized electric equipment such as electric vehicles, electric bicycles and power tools. However, the safety of lithium batteries is an important factor affecting their development.
  • the positive electrode materials of lithium-ion batteries generally include lithium-rich manganese, lithium cobalt oxide, lithium manganate, lithium nickel cobalt manganate, and lithium iron phosphate;
  • the negative electrode is generally graphite, silicon-carbon composite materials, and the charging process is when lithium ions are removed from the positive electrode material. It comes out and is embedded into the negative electrode material through the electrolyte and separator. When fully charged, the positive electrode of the lithium-ion battery has strong oxidizing properties and the negative electrode has strong reducing properties.
  • the electrolyte used is LiPF6. LiPF6 easily decomposes when heated and is sensitive to water.
  • the electrolyte solvent is generally a carbonate-based organic solvent with a low flash point. Under conditions such as overcharge, overdischarge, and overheating of the battery, it may cause It may cause thermal runaway inside the battery, causing the battery to burn or even explode.
  • One is to set up a fireproof and heat insulation device between the battery module and the upper cover.
  • the pressure relief mechanism of the battery cell explodes, causing high-temperature flames, high-temperature solids (such as isolation membranes, positive and negative electrode plates), high-temperature liquids (such as electrolytes), high-temperature gases ( For example, electrochemical reactants) will be sprayed directly towards the upper cover of the box, and then fire and heat insulation protection will be carried out through the fireproof and heat insulation device, thus avoiding the continued development of thermal runaway of a single battery cell and improving the safety performance of the battery.
  • the other is to install a flame-retardant package inside the battery cell.
  • the flame-retardant package will rupture due to heat and release the flame retardant, thus achieving safe control at the source of thermal runaway inside the battery.
  • the thickness of the pole piece will increase. Therefore, the cell assembly will produce a certain external expansion force.
  • the electrolyte side reactions of the battery cell increase.
  • the gas produced by the battery cells will further aggravate the expansion of the battery cells. Therefore, if the circulation of the battery cells is not stopped in time, it will lead to safety issues such as explosion and increased risk of combustion.
  • the applicant found that after the battery cells expand to a certain extent, the battery cells can be rendered unusable while ensuring their safety.
  • a resistance-increasing component is added to the outer casing of the battery cell.
  • the resistance-increasing component includes a sealed casing and a resistance-increasing agent sealed in the sealed casing.
  • the sealed case can be opened under the expansion pressure generated by the expansion of the battery core assembly to release the resistance-increasing agent.
  • the thickness of the cell components inside the casing increases significantly and expands.
  • the expansion pressure generated by this expansion can be applied to the resistance-increasing component, causing the sealed shell of the resistance-increasing component to open, thereby releasing the resistance-increasing component.
  • the resistance-increasing agent further reaches the position of the pole piece, causing the pole piece resistance to increase, causing the battery cell to be unable to be used normally, thus ensuring the safety of the battery cell.
  • the battery cells disclosed in the embodiments of the present application can be used in, but are not limited to, electrical devices such as vehicles, ships, or aircrafts.
  • Embodiments of the present application provide an electrical device that uses a battery as a power source.
  • the electrical device may be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, a battery car, an electric vehicle, a ship, a spacecraft, etc.
  • electric toys can include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, electric airplane toys, etc.
  • spacecraft can include airplanes, rockets, space shuttles, spaceships, etc.
  • an electric device 1000 according to an embodiment of the present application is used as an example.
  • FIG. 1 is a schematic structural diagram of a vehicle 1000 provided by some embodiments of the present application.
  • the vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc.
  • the battery 100 is disposed inside the vehicle 1000 , and the battery 100 may be disposed at the bottom, head, or tail of the vehicle 1000 .
  • the battery 100 may be used to power the vehicle 1000 , for example, the battery 100 may serve as an operating power source for the vehicle 1000 .
  • the vehicle 1000 may also include a controller 200 and a motor 300 .
  • the controller 200 is used to control the battery 100 to provide power to the motor 300 , for example, for starting, navigating and driving the vehicle 1000 .
  • the battery 100 can not only be used as an operating power source for the vehicle 1000 , but also can be used as a driving power source for the vehicle 1000 , replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000 .
  • FIG. 2 is an exploded view of the battery 100 provided by some embodiments of the present application.
  • the battery 100 includes a case 10 and battery cells 20 , and the battery cells 20 are accommodated in the case 10 .
  • the box 10 is used to provide an accommodation space for the battery cells 20, and the box 10 can adopt a variety of structures.
  • the box 10 may include a first part 11 and a second part 12 , the first part 11 and the second part 12 cover each other, and the first part 11 and the second part 12 jointly define a space for accommodating the battery cells 20 of accommodation space.
  • the second part 12 may be a hollow structure with one end open, and the first part 11 may be a plate-like structure.
  • the first part 11 covers the open side of the second part 12 so that the first part 11 and the second part 12 jointly define a receiving space.
  • the first part 11 and the second part 12 may also be hollow structures with one side open, and the open side of the first part 11 is covered with the open side of the second part 12.
  • the box 10 formed by the first part 11 and the second part 12 can be in various shapes, such as cylinder, rectangular parallelepiped, etc.
  • the battery 100 there may be a plurality of battery cells 20, and the plurality of battery cells 20 may be connected in series, in parallel, or in mixed connection.
  • Mixed connection means that the plurality of battery cells 20 are connected in series and in parallel.
  • the plurality of battery cells 20 can be directly connected in series or in parallel or mixed together, and then the whole composed of the plurality of battery cells 20 can be accommodated in the box 10 ; of course, the battery 100 can also be a plurality of battery cells 20 First, the battery modules are connected in series, parallel, or mixed to form a battery module, and then multiple battery modules are connected in series, parallel, or mixed to form a whole, and are accommodated in the box 10 .
  • the battery 100 may also include other structures.
  • the battery 100 may further include a bus component for realizing electrical connections between multiple battery cells 20 .
  • Each battery cell 20 may be a secondary battery or a primary battery; it may also be a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery, but is not limited thereto.
  • the battery cell 20 may be in the shape of a cylinder, a flat body, a rectangular parallelepiped or other shapes.
  • FIG. 3 is an exploded structural diagram of a battery cell 20 provided in some embodiments of the present application.
  • the battery cell 20 refers to the smallest unit that constitutes the battery.
  • the battery cell 20 includes a top cover 21 , a case 22 , a cell assembly 23 and other functional components.
  • the top cover 21 refers to a component that covers the opening of the case 22 to isolate the internal environment of the battery cell 20 from the external environment.
  • the shape of the top cover 21 can be adapted to the shape of the housing 22 to fit the housing 22 .
  • the top cover 21 can be made of a material with a certain hardness and strength (such as aluminum alloy). In this way, the top cover 21 is less likely to deform when subjected to extrusion and collision, so that the battery cell 20 can have higher durability. Structural strength and safety performance can also be improved.
  • Functional components such as electrode terminals 211 may be provided on the top cover 21 . The electrode terminal 211 can be used to electrically connect with the battery cell assembly 23 for outputting or inputting electric energy of the battery cell 20 .
  • the top cover 21 may also be provided with a pressure relief mechanism for releasing the internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold.
  • the top cover 21 can also be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which are not particularly limited in the embodiment of the present application.
  • an insulating member may also be provided inside the top cover 21 , and the insulating member may be used to isolate the electrical connection components in the housing 22 from the top cover 21 to reduce the risk of short circuit.
  • the insulating member may be plastic, rubber, etc.
  • the housing 22 is a component used to cooperate with the top cover 21 to form an internal environment of the battery cell 20 , wherein the formed internal environment can be used to accommodate the battery core assembly 23 , electrolyte, and other components.
  • the housing 22 and the top cover 21 may be independent components, and an opening may be provided on the housing 22.
  • the top cover 21 covers the opening at the opening to form an internal environment of the battery cell 20.
  • the top cover 21 and the housing 22 can also be integrated. Specifically, the top cover 21 and the housing 22 can form a common connection surface before other components are put into the housing. When it is necessary to encapsulate the inside of the housing 22 When, the top cover 21 covers the housing 22 again.
  • the housing 22 can be of various shapes and sizes, such as rectangular parallelepiped, cylinder, hexagonal prism, etc. Specifically, the shape of the housing 22 can be determined according to the specific shape and size of the battery core assembly 23 .
  • the housing 22 may be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which are not particularly limited in the embodiments of the present application.
  • the battery cell assembly 23 is a component in the battery cell 20 that undergoes electrochemical reactions.
  • One or more battery core assemblies 23 may be contained within the housing 22 .
  • the cell assembly 23 is mainly formed by winding or stacking positive electrode sheets and negative electrode sheets, and a separator is usually provided between the positive electrode sheets and the negative electrode sheets.
  • the portions of the positive electrode sheet and the negative electrode sheet that contain active material constitute the main body of the battery assembly, and the portions of the positive electrode sheet and the negative electrode sheet that do not contain active material constitute the tabs 231 respectively.
  • the positive electrode tab and the negative electrode tab can be located together at one end of the main body or respectively located at both ends of the main body.
  • the positive active material and the negative active material react with the electrolyte, and the tabs 231 are connected to the electrode terminals to form a current loop.
  • FIG. 4 is a schematic three-dimensional structural diagram of a flame-retardant structure according to some embodiments of the present application.
  • the battery cell 20 includes a casing 24 , a cell assembly 23 and a resistance increasing member 25 .
  • the housing 24 has a receiving cavity 241 .
  • the battery core assembly 23 is located in the accommodation cavity 241 .
  • the resistance increasing component 25 is located in the accommodation cavity 241 and includes a sealing shell 251 and a resistance increasing agent 252 .
  • the resistance increasing agent 252 is sealed in the sealed housing 251 .
  • the sealed case 251 can be opened under the expansion pressure generated by the expansion of the battery core assembly 23 to release the resistance increasing agent 252 .
  • the sealed housing 251 of the resistance increasing member 25 refers to a housing that can seal and protect the resistance increasing agent 252 .
  • the sealing housing 251 can prevent the resistance increasing agent 252 from leaking into the accommodation cavity 241 in advance.
  • the sealing housing 251 may be bag-shaped, box-shaped, spherical or other irregular shapes, which are not limited here.
  • the fact that the sealed housing 251 can be opened under the expansion pressure generated by the expansion of the battery core assembly 23 means that the sealed housing 251 can be opened directly or indirectly under the expansion pressure generated by the expansion of the battery core assembly 23 .
  • the sealing case 251 can be opened directly under the expansion pressure generated by the expansion of the battery core assembly 23
  • the expansion pressure directly acts on the sealing case 251, so that the sealing case 251 is forced to open.
  • the opening method can be a sealing method.
  • the damaged housing 251 can be directly broken and opened, or the switch structure on the sealed housing 251 can be opened.
  • the switch structure can be a valve body or a cover body, which is not limited here.
  • the sealing case 251 When the sealing case 251 can be opened indirectly under the expansion pressure generated by the expansion of the battery core assembly 23, the expansion pressure indirectly acts on the sealing case 251, so that the sealing case 251 is forced to open.
  • the indirect method may be: This is achieved through some auxiliary structures that open the sealed housing 251.
  • the resistance-increasing member 25 By arranging the resistance-increasing member 25 in the casing 24 of the battery cell 20 , in the later period of the cycle of the battery cell 20 , the cell assembly 23 inside the casing 24 expands and the thickness increases. The expansion pressure generated by the expansion can be applied to the increased resistance. on the resistance member 25, so that the sealed housing 251 of the resistance-increasing member 25 is opened, thereby releasing the resistance-increasing agent 252 into the accommodation cavity 241. The resistance-increasing agent 252 further reaches the position of the pole piece of the battery core assembly 23, so that the pole piece is The sheet resistance increases, causing the battery cell 20 to be unable to be used normally, so the safety of the battery cell 20 can be ensured.
  • the housing includes a top cover 21 and a housing 22 .
  • the top cover 21 covers the housing 22 and together with the housing 22 forms an accommodation cavity 241 .
  • the resistance increasing agent 252 includes at least one of silicone oil or tetrafluoroethylene emulsion.
  • Both silicone oil and tetrafluoroethylene emulsion have insulating properties. After being released into the accommodation cavity 241, they can increase the resistance of the electrolyte to ensure that the battery cells 20 cannot be used normally, and the silicone oil and tetrafluoroethylene emulsion have good chemical stability. Therefore, it can be stored in the sealed case 251 for a long time without qualitative change, which improves the reliability of the resistance-increasing effect of the resistance-increasing component 25 .
  • silicone oil and tetrafluoroethylene emulsion can be used as thermal conductive agents. After being released into the accommodation cavity 241, they can quickly conduct the heat generated inside the accommodation cavity 241 to the outer shell 24, thus speeding up heat dissipation and reducing the risk of combustion.
  • silicone oil includes dimethyl silicone oil, ethyl silicone oil, phenyl silicone oil, methyl hydrogenated silicone oil, methyl phenyl silicone oil, methyl chlorophenyl silicone oil, methyl ethoxy At least one of base silicone oil, methyltrifluoropropyl silicone oil, methylvinyl silicone oil, methylhydroxy silicone oil, ethyl hydrogen-containing silicone oil, hydroxyl hydrogen-containing silicone oil, and cyanide-containing silicone oil.
  • the above-mentioned silicone oil types all have excellent heat resistance and small surface tension, which can avoid being affected by the high temperature of the battery cells 20 and are easily mixed into the electrolyte, thereby improving the reliability of the resistance-increasing effect of the resistance-increasing component 25 .
  • the mass of the resistance increasing agent 252 is m
  • the capacity of the battery cell 20 is x
  • m is 0.4 to 0.6 times of x.
  • the applicant's research has found that when the mass m of the resistance increasing agent 252 is 0.4 to 0.6 times the capacity x of the battery cell 20, the resistance increasing effect can be fully exerted to ensure that the battery cell 20 cannot be used normally.
  • the mass m of the resistance increasing agent 252 is 0.5 times the capacity x of the battery cell 20 .
  • Table 1 shows the effect of the mass m of the resistance increasing agent 252 in this application on the resistance of the battery cell 20 .
  • the resistance increasing agent 252 is made of the same material, and the sealing shell 251 is also made of the same material.
  • the size of the resistance increasing member 25 along the direction of the expansion pressure is determined according to the ratio of the bursting pressure value of the resistance increasing member 25 to the bursting coefficient of the resistance increasing member 25 .
  • the rupture coefficient of the resistance increasing member 25 may refer to the tearing strength of the sealing shell 251, and the tearing strength may be tested by the Elemendorff method.
  • the size of the resistance increasing member 25 along the direction of the expansion pressure can be clarified, thereby ensuring that the sealing shell 251 can rupture and open in the later stages of the cycle, thereby ensuring that Safety of battery cells 20 .
  • the rupture pressure value is determined based on the sum of the pressure value of the resistance-increasing agent acting on the sealed shell along the direction of gravity and the pressure value of the expansion pressure acting on the sealed shell.
  • the pressure at the bottom of the sealed case 251 will be greater than the pressure in other parts, and the sealed case 251 will also be affected by the expansion pressure, so the combined effect of the two Under strong force, the most vulnerable part of the sealing housing 251 to break is the bottom of the sealing housing 251 .
  • the rupture pressure value can be determined by the sum of the pressure value of the resistance increasing agent acting on the sealing shell 251 along the direction of gravity and the pressure value of the expansion pressure acting on the sealing shell 251, thereby determining the expansion pressure of the resistance increasing member 25 along the direction of gravity.
  • the size of the direction is to ensure that the installed sealing housing 251 can be broken and opened later in the cycle.
  • d is the wall thickness of the sealed shell 251
  • ⁇ is the density of the resistance increasing agent 25
  • g is the acceleration of gravity
  • c is the height of the resistance increasing member 25
  • ⁇ is the rupture coefficient of the resistance increasing member 25
  • b is the resistance increasing member 25. width of 25;
  • F is the pressure value of the cell assembly 23 acting on the resistance increasing member 25. F is greater than or equal to 18,000 Newtons and less than or equal to 22,000 Newtons.
  • the height of the resistance-increasing member 25 refers to the vertical dimension as shown in Figure 4 , specifically the size along the height direction of the battery cell 20
  • the width of the resistance-increasing member 25 refers to the dimension as shown in Figure 4
  • the horizontal dimensions shown are specifically the dimensions along the width direction of the battery cell 20 .
  • the wall thickness of the sealed case 251 is confirmed through the above formula, which can ensure that in the later period of the cycle of the battery cell 20, the resistance increasing member 25 can open under the action of the expansion pressure to release the resistance increasing agent 252, further improving the resistance increasing Part 25 set the reliability.
  • the value of F is 20,000 Newtons.
  • the rupture pressure value can be obtained according to the following formula:
  • P is the burst pressure value of the resistance increasing member 25
  • P1 is the pressure value of the resistance increasing agent 252 acting on the sealing shell 251 along the direction of gravity
  • P2 is the pressure value of the expansion pressure acting on the sealing shell 251
  • V is The volume of the resistance increasing member 25.
  • the battery cell 20 further includes a battery cell assembly 23 , which is disposed in the accommodation cavity 241 , and the resistance increasing member 25 is disposed between the inner wall of the housing 24 and the battery cell assembly 23 . between.
  • the resistance increasing member 25 By arranging the resistance increasing member 25 between the inner wall of the housing 24 and the cell assembly 23, when the cell assembly 23 expands, the side of the resistance increasing member 25 facing away from the cell assembly 23 is blocked by the housing 24. position, so that the expansion force is reliably exerted on the resistance increasing member 25, further ensuring that the sealing housing 251 of the resistance increasing member 25 can be opened.
  • the resistance increasing member 25 is fixed on the inner wall of the housing 24 .
  • the resistance increasing member 25 can be bonded to the inner wall of the housing 24 .
  • the resistance-increasing member 25 can be maintained in position within the housing 24 without being easily affected by external forces and causing positional deviation, thereby allowing the pressure in the accommodation cavity 241 to accurately act on the resistance-increasing member 25 .
  • the resistance increasing member 25 covers the battery core assembly 23 toward the orthographic projection of the battery core assembly 23 .
  • the resistance-increasing component 25 can fully accept the expansion force from the battery cell assembly 23 , which improves the reliability of the resistance-increasing component 25 opening and releasing the resistance-increasing agent 252 at the later stage of the cycle of the battery cell 20 .
  • the housing 24 includes adjacent first side walls 242 and second side walls 243 .
  • the first side wall 242 is connected to one side of the second side wall 243 .
  • the first side wall 242 The area is larger than the area of the second side wall 243 .
  • the resistance increasing member 25 is disposed between the first side wall 242 and the battery core assembly 23 .
  • the resistance increasing member 25 By disposing the resistance increasing member 25 between the larger first side wall 242 and the cell assembly 23, the resistance increasing member 25 can have a larger force-bearing area, thereby actively responding to the pressure changes in the accommodation cavity 241. This improves the reliability of the resistance-increasing component 25 opening and releasing the resistance-increasing agent 252 at the end of the cycle of the battery cell 20 .
  • the housing 24 includes two first side walls 242 oppositely arranged along the first direction and two second side walls 243 oppositely arranged along the second direction.
  • the first direction intersects the second direction, and the two first side walls 243 are oppositely arranged along the second direction.
  • the side wall 242 and the two second side walls 243 are connected to each other to enclose the accommodation cavity 221 .
  • the first direction is the width direction of the battery cell 20
  • the second direction is the length direction of the battery cell 20 .
  • the resistance increasing member 25 includes two, and each resistance increasing member 25 is provided between a corresponding first side wall 242 and the inner wall of the housing 24 .
  • the resistance increasing members 25 may also include three, four, etc., which are not limited here.
  • the mass m of all resistance-increasing agents 252 is 0.4 to 0.6 times the capacity x of the battery cell 20 . are the same.
  • the height and length of the resistance increasing member 25 may be equal to the height and length of the first side wall 242 respectively. In this way, the stress-bearing area can be maximized and the reliability of rupture is improved.
  • the battery cell 20 further includes a plurality of battery core components 23 , all the battery core components 23 are provided in the accommodation cavity 241 , and the resistance increasing member 25 is provided on two adjacent battery cells. between components 23.
  • the opposite sides of the resistance increasing member 25 can receive the force from the battery core assembly 23, further ensuring that The sealed housing 251 of the resistance increasing member 25 can be opened.
  • the resistance-increasing member 25 includes multiple resistance-increasing members 25 , at least one resistance-increasing member 25 is provided between the inner wall of the housing 24 and the battery core assembly 23 , and at least one resistance-increasing member 25 is provided between two adjacent cells. between core components 23.
  • the battery cell 20 further includes an auxiliary component.
  • the auxiliary component is provided in the accommodation cavity 241.
  • the sealed housing 251 can move relative to the auxiliary component under the pressure generated in the accommodation cavity 241. Open with auxiliary parts.
  • Auxiliary parts refer to components that assist the opening of the sealing housing 251, so as to be more conducive to the opening of the sealing housing 251.
  • the direction of the pressure generated in the accommodation cavity 241 can be clarified or the pressure effect generated in the accommodation cavity 241 can be strengthened, so that the sealed housing 251 can be opened more easily.
  • the auxiliary member may be fixed on the inner wall of the housing 24.
  • the auxiliary component can be fixed on the battery core component 23 .
  • the auxiliary components include a plurality of auxiliary components, and all auxiliary components are spaced apart from each other. By arranging multiple auxiliary parts, they can act on the sealing housing 251 at the same time, ensuring that the sealing housing 251 can be successfully opened after the cycle.
  • the auxiliary component includes a sharp portion, which is disposed toward the sealing housing 251 and capable of piercing the sealing housing 251 .
  • the pressure effect generated in the accommodation cavity 241 is strengthened, making the sealed housing 251 easier to open, and the method of setting the sharp portion is also simple.
  • the sharp portion can be tapered or needle-shaped, which is not limited here.
  • the resistance-increasing component 25 further includes a flame retardant, and the flame retardant is provided in the sealed housing 251 .
  • the flame retardant By setting the flame retardant, the flame retardant can be released by opening the sealing case 251 in the later period of the cycle, so that when there is abnormal gas production inside the battery cell 20, the flame retardant can be promptly sprinkled on the surface of the cell assembly 23, thereby causing the problem. It has the dual functions of prevention and fire extinguishing, thereby reducing the risk of combustion.
  • the flame retardant includes at least one of an organic liquid flame retardant or an inorganic liquid flame retardant.
  • Liquid flame retardants are liquid at room temperature and can vaporize at high temperatures, evaporating a large amount of fire heat and having a good cooling effect.
  • the flame retardant includes perfluorohexanone flame retardant, alkyl phosphate flame retardant, heptafluoropropane flame retardant, phosphorus nitrogen-based flame retardant, nitrogen-based flame retardant or silicon-based flame retardant. at least one of the agents.
  • the flame retardant includes at least one of perfluorohexanone flame retardant, alkyl phosphate flame retardant, heptafluoropropane flame retardant, phosphorus nitrogen flame retardant, nitrogen flame retardant or silicon flame retardant. , can quickly vaporize at high temperatures and improve the rapidity of cooling.
  • the resistance increasing member 25 further includes a dispersant 253 , and the dispersant 253 is provided in the sealed housing 251 .
  • the dispersant 253 and the resistance-increasing agent 252 can be released simultaneously by opening the sealing shell 251 at the later stage of the cycle, so that the resistance-increasing agent 252 can be quickly and evenly dispersed into the container under the action of the dispersant 253.
  • the inside of the cavity 241 especially between the pole pieces and even on the surface of the particles, can quickly and reliably increase the resistance of the pole pieces to ensure the safety of the battery cells 20 .
  • the dispersant 253 includes at least one of polyoxyethylene sorbitan monooleate or montmorillonite.
  • Polyoxyethylene sorbitan monooleate or montmorillonite can be evenly mixed with the resistance increasing agent, and then be quickly and evenly dispersed after release.
  • the sealed housing 251 is configured to melt and fracture when the external temperature reaches a preset temperature.
  • the battery cell 20 can not only increase the resistance in the later stages of the cycle, but also increase the resistance under thermal runaway conditions, thus having a dual role. , further improving the safety of the battery cell 20 .
  • the preset temperature is not less than 150 degrees.
  • the flame retardant when a flame retardant is present in the sealed housing 251, the flame retardant can be released when the sealed housing 251 melts and ruptures when reaching the preset temperature, thereby reducing the risk of combustion.
  • the sealed housing 251 includes one of a polyvinyl chloride housing, a polyvinyl alcohol housing, a rubber housing, a cast polypropylene film housing, and a polyethylene terephthalate housing. kind.
  • the melting points of polyvinyl chloride shells, polyvinyl alcohol shells, rubber shells, cast polypropylene film shells, and polyethylene terephthalate shells are all greater than 150 degrees, and they do not increase resistance with electrolytes or The agent, flame retardant and dispersant react and can stably accommodate the resistance increasing agent, flame retardant and dispersant.
  • polyvinyl chloride shells, polyvinyl alcohol shells, rubber shells, cast polypropylene film shells, and polyethylene terephthalate shells can also be doped with fluorine elements, chlorine elements, and sulfur elements. At least one of the elements and lead.
  • the melting temperature of the shell can be changed and its pressure-bearing capacity can be improved.
  • the present application provides a battery 100 .
  • the battery 100 includes the battery cells 20 in any of the above embodiments.
  • the resistance-increasing member 25 By arranging the resistance-increasing member 25 in the casing 24 of the battery cell 20 , in the later period of the cycle of the battery cell 20 , the cell assembly 23 inside the casing 24 expands and the thickness increases. The expansion pressure generated by the expansion can be applied to the increased resistance. on the resistance member 25, so that the sealed housing 251 of the resistance-increasing member 25 is opened, thereby releasing the resistance-increasing agent 252 into the accommodation cavity 241. The resistance-increasing agent 252 further reaches the position of the pole piece of the battery core assembly 23, so that the pole piece is The sheet resistance increases, causing the battery cell 20 to be unable to be used normally, so the safety of the battery cell 20 can be ensured.
  • the present application provides an electrical device.
  • the electric device includes the battery 100 in any of the above embodiments.
  • the resistance-increasing member 25 By arranging the resistance-increasing member 25 in the casing 24 of the battery cell 20 , in the later period of the cycle of the battery cell 20 , the cell assembly 23 inside the casing 24 expands and the thickness increases. The expansion pressure generated by the expansion can be applied to the increased resistance. on the resistance member 25, so that the sealed housing 251 of the resistance-increasing member 25 is opened, thereby releasing the resistance-increasing agent 252 into the accommodation cavity 241. The resistance-increasing agent 252 further reaches the position of the pole piece of the battery core assembly 23, so that the pole piece is The sheet resistance increases, causing the battery cell 20 to be unable to be used normally, so the safety of the battery cell 20 can be ensured.
  • the present application provides a battery cell 20 .
  • the battery cell 20 includes a battery core assembly 23, a casing 24, a resistance-increasing component 25 and auxiliary components.
  • the housing 24 has a receiving cavity 241 .
  • the battery core component 23 , the resistance increasing component 25 and the auxiliary components are all located in the accommodation cavity 241 .
  • the housing 24 includes two first side walls 242 oppositely arranged along the first direction and two second side walls 243 oppositely arranged along the second direction. The first direction intersects the second direction, and the two first side walls 242 are intersected with the second direction.
  • the two second side walls 243 are connected to each other to enclose the accommodation cavity 221 , and the area of the first side wall 242 is larger than the area of the second side wall 243 .
  • the resistance increasing member 25 includes two, and each resistance increasing member 25 is disposed between a corresponding first side wall 242 and the inner wall of the housing 24 .
  • the auxiliary component includes a cone-shaped sharp portion, which is disposed toward the sealing housing 251 and capable of piercing the sealing housing 251 .
  • Each resistance-increasing component 25 includes a sealing shell 251 , a resistance-increasing agent 252 , a flame retardant and a dispersant 253 .
  • the resistance increasing agent 252, the flame retardant and the dispersant 253 are sealed in the sealed shell 251.
  • the battery core assembly 23 can expand to provide corresponding expansion pressure to the sealing case 251.
  • the sealing case 251 can move relative to the auxiliary member under the expansion pressure, and then be pierced and opened by the auxiliary member to release the resistance increasing agent 252 and the resistance.
  • Resistance increasing agent 252 includes silicone oil.
  • the flame retardant includes at least one of an organic liquid flame retardant or an inorganic liquid flame retardant.
  • Dispersant 253 includes polyoxyethylene sorbitan monooleate.
  • the sealed housing 251 is configured to rupture when the external temperature reaches a preset temperature.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Sealing Battery Cases Or Jackets (AREA)
  • Battery Mounting, Suspending (AREA)
  • Secondary Cells (AREA)

Abstract

La présente invention concerne un élément de batterie (20), une batterie (100) et un dispositif électrique. L'élément de batterie (20) comprend : un boîtier (24) ayant une cavité de réception (241) ; et un élément d'augmentation de résistance (25) disposé dans la cavité de réception (241) et comprenant un boîtier d'étanchéité (251) et un agent d'augmentation de résistance (252), l'agent d'augmentation de résistance (252) étant scellé dans le boîtier d'étanchéité (251). Le boîtier d'étanchéité (251) peut être ouvert sous une force d'action générée par un changement de pression dans la cavité de réception (241), de façon à libérer l'agent d'augmentation de résistance (252).
PCT/CN2022/102287 2022-06-29 2022-06-29 Élément de batterie, batterie et dispositif électrique WO2024000246A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
CN202280046081.1A CN117642924A (zh) 2022-06-29 2022-06-29 电池单体、电池及用电装置
PCT/CN2022/102287 WO2024000246A1 (fr) 2022-06-29 2022-06-29 Élément de batterie, batterie et dispositif électrique

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2022/102287 WO2024000246A1 (fr) 2022-06-29 2022-06-29 Élément de batterie, batterie et dispositif électrique

Publications (1)

Publication Number Publication Date
WO2024000246A1 true WO2024000246A1 (fr) 2024-01-04

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WO (1) WO2024000246A1 (fr)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000173651A (ja) * 1998-12-09 2000-06-23 Tomiyama Pure Chemical Industries Ltd 二次電池用非水電解液
WO2014141753A1 (fr) * 2013-03-12 2014-09-18 Ｎｅｃエナジーデバイス株式会社 Module de cellule de puissance
CN110190207A (zh) * 2019-06-11 2019-08-30 珠海格力电器股份有限公司 软包电池及其制备方法
CN209607766U (zh) * 2019-02-28 2019-11-08 珠海格力电器股份有限公司 电池壳及电池
CN211555975U (zh) * 2019-12-31 2020-09-22 江苏境具净环保科技有限公司 一种电池系统
CN216213633U (zh) * 2021-10-15 2022-04-05 宁德时代新能源科技股份有限公司 电芯、电池及用电装置

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000173651A (ja) * 1998-12-09 2000-06-23 Tomiyama Pure Chemical Industries Ltd 二次電池用非水電解液
WO2014141753A1 (fr) * 2013-03-12 2014-09-18 Ｎｅｃエナジーデバイス株式会社 Module de cellule de puissance
CN209607766U (zh) * 2019-02-28 2019-11-08 珠海格力电器股份有限公司 电池壳及电池
CN110190207A (zh) * 2019-06-11 2019-08-30 珠海格力电器股份有限公司 软包电池及其制备方法
CN211555975U (zh) * 2019-12-31 2020-09-22 江苏境具净环保科技有限公司 一种电池系统
CN216213633U (zh) * 2021-10-15 2022-04-05 宁德时代新能源科技股份有限公司 电芯、电池及用电装置

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