Battery cell, battery, and electric device

Abstract

This application relates to a battery cell, a battery, and an electrical device, belonging to the field of battery manufacturing technology. This application proposes a battery cell comprising: a casing; a pressure relief component disposed on a first wall of the casing; an electrode assembly disposed inside the casing; an electrolyte immersing the electrode assembly; an encapsulation component and an active material disposed inside the casing. The encapsulation component is used to encapsulate the active material on the side of the electrode assembly near the first wall. The encapsulation component is configured to be actuated to release the active material when the internal pressure or temperature of the battery cell reaches a first threshold. The active material can react with the electrolyte and / or the electrode assembly to increase the internal pressure or temperature of the battery cell, thereby actuating the pressure relief component. The battery cell proposed in this application can rapidly release internal temperature and pressure in the event of thermal runaway, exhibiting good safety performance. This application also proposes a battery and an electrical device including the battery cell.

Description

Technical Field

[0001] This application relates to the field of battery manufacturing technology, and more specifically, to a battery cell, a battery, and an electrical device. Background Technology

[0002] With the rapid development of the new energy vehicle industry, the technological level of the lithium battery industry is also rapidly improving, which places high demands on the safety performance of individual battery cells.

[0003] When a battery cell experiences thermal runaway, its internal temperature and pressure rise sharply. If the internal temperature and pressure cannot be released in time, the battery cell may explode, causing a serious safety accident. Summary of the Invention

[0004] Therefore, this application proposes a battery cell, a battery, and an electrical device that can rapidly release internal temperature and pressure when the battery cell experiences thermal runaway, thus exhibiting good safety performance.

[0005] A first aspect of this application provides a battery cell, comprising: a housing; a pressure relief element disposed on a first wall of the housing; an electrode assembly disposed inside the housing; an electrolyte immersing the electrode assembly; an encapsulation element and an active material disposed inside the housing, wherein the encapsulation element is used to encapsulate the active material on a side of the electrode assembly near the first wall, and the encapsulation element is configured to be actuated to release the active material when the internal pressure or temperature of the battery cell reaches a first threshold, the active material being capable of reacting with the electrolyte and / or the electrode assembly to increase the internal pressure or temperature of the battery cell, thereby actuating the pressure relief element.

[0006] In the battery cell of this application embodiment, an active material is encapsulated near the pressure relief component. When thermal runaway occurs at a certain part inside the battery cell, the encapsulation component is actuated before the temperature or pressure inside the battery reaches the actuation threshold of the pressure relief component, releasing the active material. This causes thermal runaway to occur on the side of the electrode assembly closest to the pressure relief component, resulting in the electrode assembly breaking down and decomposing, accompanied by the generation of a large amount of high-temperature, high-pressure gas. This rapidly increases the temperature or pressure near the pressure relief component, actuating it to release the pressure or temperature inside the battery cell. In particular, when the thermal runaway location of the battery cell is far from the pressure relief component, releasing the active material into the battery cell ensures that the pressure relief component is effectively actuated when thermal runaway occurs inside the battery cell, smoothly releasing the pressure or temperature inside the battery cell, thus giving the battery cell higher safety performance.

[0007] According to some embodiments of this application, the pressure relief element is configured to be actuated to release pressure when the internal pressure or temperature of the battery cell reaches a second threshold, the second threshold being greater than the first threshold.

[0008] In the above scheme, both the pressure relief component and the encapsulation component are actuated by pressure rupture, and the actuation threshold of the pressure relief component is greater than that of the encapsulation component. This can reliably enable the encapsulation component to be actuated before the pressure relief component, so as to release the internal pressure of the battery cell through the pressure relief component, thereby giving the battery cell better safety performance.

[0009] According to some embodiments of this application, the active substance is an oxidant.

[0010] In the above scheme, an oxidant is used to react with the electrode assembly and / or electrolyte. The reaction is rapid and intense, which can break down and decompose the electrode assembly and generate a large amount of high temperature and high pressure gas, ensuring the activation of the pressure relief device and allowing the pressure or temperature of the thermal runaway part inside the battery cell to be discharged smoothly through the pressure relief device.

[0011] According to some embodiments of this application, the active substance includes at least one of potassium permanganate, potassium dichromate, sodium hypochlorite, hydrogen peroxide, lead dioxide, periodic acid, cobalt trifluoride, and sodium ferrate.

[0012] In the above-mentioned scheme, the active substances of the above types will not react with the shell and the encapsulation, and are common oxidants that are easy to obtain and inexpensive.

[0013] According to some embodiments of this application, the encapsulation encapsulates at least a portion of the active material at a position corresponding to the pressure relief element.

[0014] In the above scheme, the active material not only triggers a chemical reaction near the pressure relief device to actuate the pressure relief device, but also triggers a chemical reaction in other locations inside the battery cell to break the corresponding electrode components, so that the exhaust channel from the thermal runaway part of the battery cell to the pressure relief device is unobstructed, so that the gas generated at the thermal runaway part of the battery cell can be smoothly discharged through the pressure relief device.

[0015] According to some embodiments of this application, the outer shell is provided with a pressure relief hole, the pressure relief component and the encapsulation component both cover the pressure relief hole, the encapsulation component is disposed on the side of the pressure relief component near the electrode assembly, and the encapsulation component, the pressure relief component and the hole wall of the pressure relief hole together define a closed space for accommodating the active material.

[0016] In the above scheme, the active material is encapsulated in the pressure relief hole, which does not occupy too much space inside the battery cell, thereby maintaining the original energy density of the battery cell; and when the encapsulation is actuated, the active material is released, which can trigger a chemical reaction near the pressure relief hole, reliably actuating the pressure relief device, so that the battery cell has better safety performance.

[0017] According to some embodiments of this application, both the pressure relief component and the encapsulation component are sheet-like.

[0018] In the above scheme, both the pressure relief component and the encapsulation component are sheet-shaped, which can occupy a small space in the pressure relief hole, thereby allowing more space to be stored in the pressure relief hole for active materials.

[0019] According to some embodiments of this application, the encapsulation is made of insulating material and is disposed between the first wall and the electrode assembly to insulate and isolate the electrode assembly and the first wall.

[0020] In the above scheme, the encapsulation component is not only used to encapsulate the active material, but also to insulate and isolate the electrode assembly and the first wall, so that the encapsulation component integrates the insulation function and the function of encapsulating the active material, reducing the number of components inside the battery cell, making the battery cell structure compact and having a high energy density.

[0021] According to some embodiments of this application, the package has a first receiving cavity corresponding to the position of the pressure relief member, and at least a portion of the active material is packaged within the first receiving cavity.

[0022] In the above scheme, when the package is actuated, it can release the active material in the first cavity, triggering a chemical reaction near the pressure relief component, which can reliably actuate the pressure relief component and give the battery cell better safety performance.

[0023] According to some embodiments of this application, the first receiving cavity has a first opening, and the first wall and the pressure relief member together close the first opening.

[0024] In the above scheme, the first wall, the pressure relief component, and the encapsulation component together form a closed first accommodating cavity, which not only encapsulates the active material near the pressure relief component, but also allows the active material to trigger a chemical reaction near the pressure relief component when it is released, and makes it easy to encapsulate the active material.

[0025] According to some embodiments of this application, the first wall is rectangular, and the package further has two second receiving cavities. Along the length direction of the first wall, the two second receiving cavities are respectively located on both sides of the first receiving cavity; a portion of the active material is packaged in the first receiving cavity, and another portion is packaged in the two second receiving cavities.

[0026] In the above scheme, along the length of the first wall, a second receiving cavity is provided on both sides of the first receiving cavity. The second receiving cavity contains a portion of active material. When the active material in the second receiving cavity is released, it can trigger a chemical reaction at the corresponding position of the electrode assembly, so that the side of the electrode assembly near the pressure relief device is fully broken, and the exhaust channel from the thermal runaway part of the battery cell to the pressure relief device remains unobstructed.

[0027] According to some embodiments of this application, the second receiving cavity has a second opening, and the first wall closes the second opening.

[0028] In the above scheme, the first wall and the encapsulation component together form a closed second containment cavity, which can trigger a chemical reaction at the corresponding position when the active material is released, and it is easy to encapsulate the active material.

[0029] According to some embodiments of this application, the housing includes a shell and an end cap. The shell has an opening. The shell includes a side wall and a bottom wall. The bottom wall is disposed opposite to the opening. The end cap is connected to the side wall and covers the opening. The first wall is the end cap, the bottom wall, or the side wall.

[0030] In the above scheme, the first wall is an end cap, bottom wall, or side wall, and the first wall is equipped with a pressure relief component. When thermal runaway occurs in a certain part inside the battery cell, the encapsulation component is actuated before the temperature or pressure inside the battery reaches the actuation threshold of the pressure relief component, so as to release the active material, causing the part of the electrode assembly near the pressure relief component to break down and decompose under chemical reaction; and the chemical reaction is accompanied by the generation of a large amount of high temperature and high pressure gas, which causes the temperature or pressure near the pressure relief component to rise rapidly, so as to actuate the pressure relief component and release the pressure or temperature inside the battery cell.

[0031] A second aspect of this application provides a battery comprising the battery cell described in the first aspect of this application.

[0032] Due to the characteristics of the battery cell described in the first aspect of this application, the battery in the second aspect of this application also has good safety performance.

[0033] A third aspect of this application provides an electrical device including the battery described in the second aspect of this application.

[0034] Due to the characteristics of the battery described in the second aspect embodiment of this application, the electrical device in the third aspect embodiment of this application also has good safety performance.

[0035] The fourth aspect of this application provides a method for manufacturing a single battery cell, comprising:

[0036] A housing is provided, wherein a pressure relief element is provided on the first wall of the housing;

[0037] Provide electrode assemblies;

[0038] Provide electrolyte;

[0039] An encapsulation component and an active material are provided. The encapsulation component is used to encapsulate the active material. The encapsulation component is configured to be actuated to release the active material when the internal pressure or temperature of the battery cell reaches a first threshold. The active material is capable of reacting with the electrolyte and / or the electrode assembly to increase the internal pressure or temperature of the battery cell, thereby actuating the pressure relief component.

[0040] The electrode assembly is disposed within the housing, the active material is encapsulated in the side of the electrode assembly near the first wall using the encapsulation component, and the electrolyte is injected into the housing.

[0041] The fifth aspect of this application provides an apparatus for manufacturing a single battery cell, comprising:

[0042] A first providing device is used to provide a housing, the first wall of which is provided with a pressure relief element;

[0043] A second providing device is used to provide electrode assemblies;

[0044] The third supply device is used to supply electrolyte;

[0045] A fourth providing device is used to provide an encapsulation and an active material, the encapsulation being used to encapsulate the active material, the encapsulation being configured to be actuated to release the active material when the internal pressure or temperature of the battery cell reaches a first threshold, the active material being capable of reacting with the electrolyte and / or the electrode assembly to increase the internal pressure or temperature of the battery cell, thereby actuating the pressure relief device;

[0046] The mounting module is used to place the electrode assembly inside the housing, encapsulate the active material in the side of the electrode assembly near the first wall using the encapsulation component, and inject the electrolyte into the housing.

[0047] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0048] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0049] Figure 1 The diagram shown is a simplified schematic of a vehicle according to one embodiment of this application;

[0050] Figure 2 What is shown is Figure 1 A schematic diagram of the battery structure in a Chinese vehicle;

[0051] Figure 3 The diagram shown is a structural schematic of a first-form battery cell according to some embodiments of this application;

[0052] Figure 4 What is shown is Figure 3 A schematic diagram of the structure of a single battery cell with an end cap connected to electrode terminals, a pressure relief component, and a packaging component;

[0053] Figure 5 for Figure 4 AA section view in the middle;

[0054] Figure 6 The diagram shown is a structural schematic of a second form of battery cell according to some embodiments of this application;

[0055] Figure 7 What is shown is Figure 6 A schematic diagram of the structure of a battery cell with an end cap connected to electrode terminals, a pressure relief component, and a packaging component;

[0056] Figure 8 for Figure 7 BB cross-section view in the middle;

[0057] Figure 9 for Figure 8 A magnified view of a portion at point C (showing the first type of first-class accommodating cavity).

[0058] Figure 10 What is shown is Figure 6 A schematic diagram of the structure of the first accommodating cavity in the second form of a single battery cell;

[0059] Figure 11 What is shown is Figure 6 A schematic diagram of the third type of first accommodating cavity for a single battery cell;

[0060] Figure 12 What is shown is Figure 11 A schematic diagram of the encapsulation component corresponding to the first receiving cavity of the third type of battery cell.

[0061] Figure 13 for Figure 8 A magnified view of a section at point D;

[0062] The above figures are not provided to scale.

[0063] Icons: 1000 - Vehicle; 100 - Battery; 10 - Battery cell; 11 - Casing; 111 - Shell; 1111 - Bottom wall; 1112 - Side wall; 112 - End cap; 1121 - Pressure relief hole; 11211 - Hole wall; 1122 - First side; 1123 - Second side; 1124 - First part; 1125 - Second part; 1126 - Enclosed space; 113 - Opening; 12 - Electrode assembly; 121 - Main body ; 122-Electrode tab; 13-Pressure relief component; 14-Electrode terminal; 15-Encapsulation component; 151-First groove; 1512-First receiving cavity; 1513-Storage section; 152-Second groove; 1522-Second receiving cavity; 153-Connecting part; 154-Supporting part; 155-Exhaust space; 16-Active substance; 20-Box body; 21-First box body; 22-Second box body; 200-Controller; 300-Motor. Detailed Implementation

[0064] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0065] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0066] In this application, the term "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0067] In the description of this application, it should be noted that unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0068] In this application, "multiple" means two or more (including two).

[0069] In this application, the battery cell may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, etc., and the embodiments of this application are not limited to these. The battery cell may be cylindrical, flat, cuboid, or other shapes, etc., and the embodiments of this application are not limited to these. Battery cells are generally divided into three types according to their packaging method: cylindrical battery cells, prismatic battery cells, and pouch battery cells.

[0070] The battery mentioned in the embodiments of this application refers to a single physical module comprising one or more battery cells to provide higher voltage and capacity. For example, the battery mentioned in this application may include a battery module or a battery pack. A battery generally includes a housing for encapsulating one or more battery cells, which prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0071] A single battery cell includes an electrode assembly and an electrolyte. The electrode assembly consists of a positive electrode, a negative electrode, and a separator. The battery cell primarily functions by the movement of metal ions between the positive and negative electrodes. The positive electrode includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive current collector, and the uncoated positive current collector protrudes beyond the coated one, serving as the positive electrode tab. Taking a lithium-ion battery as an example, the positive current collector can be made of aluminum, and the positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode includes a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative current collector, and the uncoated negative current collector protrudes beyond the coated one, serving as the negative electrode tab. The negative electrode current collector can be made of copper, and the negative electrode active material can be carbon or silicon, etc. To ensure that a large current can pass through without melting, there are multiple positive electrode tabs stacked together, and there are multiple negative electrode tabs stacked together. The separator can be made of PP (polypropylene) or PE (polyethylene), etc. In addition, the electrode assembly can be a wound structure or a stacked structure, and the embodiments of this application are not limited to these.

[0072] Each battery cell also includes a pressure relief device, which is activated when the internal pressure of the battery cell reaches a threshold. The threshold design varies depending on the design requirements. The threshold may depend on one or more of the materials used in the positive electrode, negative electrode, electrolyte, and separator of the battery cell. The pressure relief device can take the form of an explosion-proof valve, gas valve, pressure relief valve, or safety valve, and can specifically employ pressure-sensitive or temperature-sensitive elements or structures. That is, when the internal pressure or temperature of the battery cell reaches the threshold, the pressure relief device actuates or a weak structure within the pressure relief device is damaged, thereby creating an opening or channel for the internal pressure or temperature to be released.

[0073] The term "actuation" as used in this application refers to the activation of a pressure relief component, causing it to move or be activated to a certain state, thereby releasing the internal pressure and temperature of the battery cell. The actions of the pressure relief component may include, but are not limited to, at least a portion of the component rupturing, breaking, tearing, or opening. When the pressure relief component is activated, the high-temperature, high-pressure substances inside the battery cell are discharged as waste from the opened portion. This method allows for pressure and temperature relief within the battery cell under controllable pressure or temperature, thereby preventing potentially more serious accidents.

[0074] In related technologies, when thermal runaway occurs inside a battery cell, the pressure or temperature inside the battery cell begins to rise. When the pressure or temperature inside the battery cell rises to a threshold that causes the pressure relief device to actuate, at least a part of the pressure relief device ruptures, breaks, is torn, or opens, and the high-temperature and high-pressure material inside the battery cell is discharged outward from the opened part, thereby avoiding potential more serious accidents.

[0075] The inventors discovered through research that when the thermal runaway of a battery cell is far from the pressure relief device, for example, when the thermal runaway site is located on the side of the electrode assembly away from the pressure relief device, the reaction force generated by the thermal runaway will push the electrode assembly toward the pressure relief device to block it. This will prevent the pressure relief device from being effectively activated, and the high-temperature and high-pressure gas inside the battery cell will not be able to escape from the pressure relief device, thus causing the battery cell to explode.

[0076] Based on the above ideas, this application proposes a new technical solution that can effectively actuate the pressure relief device even when the thermal runaway site is far from the pressure relief device, so as to quickly release the pressure or temperature inside the battery cell and enable the battery cell to have high safety performance.

[0077] It is understood that the battery cells described in the embodiments of this application can directly supply power to electrical devices, or they can be connected in parallel or series to form a battery to supply power to various electrical devices in the form of a battery.

[0078] It is understood that the electrical devices using battery cells or batteries described in the embodiments of this application can take many forms, such as mobile phones, portable devices, laptops, electric vehicles, electric cars, ships, spacecraft, electric toys, and power tools, etc. For example, spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers.

[0079] The battery cells and batteries described in the embodiments of this application are not limited to the electrical devices described above, but can also be applied to all electrical devices that use battery cells and batteries. However, for the sake of brevity, the following embodiments are all illustrated using electric vehicles as an example.

[0080] Figure 1 The diagram shown is a simplified schematic of a vehicle according to one embodiment of this application. Figure 2 What is shown is Figure 1 A schematic diagram of the battery structure in a Chinese vehicle.

[0081] like Figure 1 As shown, the vehicle 1000 is equipped with a battery 100, a controller 200, and a motor 300. For example, the battery 100 can be installed at the bottom, front, or rear of the vehicle 1000. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc.

[0082] In some embodiments of this application, the battery 100 can be used to power the vehicle 1000; for example, the battery 100 can serve as the operating power source for the vehicle 1000. The controller 200 is used to control the power supply provided by the battery 100 to the motor 300, for example, to meet the power requirements of the vehicle 100 during startup, navigation, and driving.

[0083] In other embodiments, the battery 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0084] In this application, the battery 100 mentioned in the embodiments refers to a single physical module comprising one or more battery cells 10 to provide higher voltage and capacity. For example, the battery 100 is composed of multiple battery cells 10 connected in series or in parallel.

[0085] like Figure 2 As shown, the battery 100 includes multiple battery cells 10 and a housing 20, with the battery cells 10 placed inside the housing 20. The housing 20 includes a first housing 21 and a second housing 22, which are closed together to form a cavity for the battery 100, within which the battery cells 10 are placed. The shapes of the first housing 21 and the second housing 22 can be determined based on the combined shape of the multiple battery cells 10, and both the first housing 21 and the second housing 22 may have an opening 113. For example, both the first housing 21 and the second housing 22 can be hollow cuboids with only one open side each. The openings 113 of the first housing 21 and the second housing 22 are opposite to each other, and the first housing 21 and the second housing 22 are interlocked to form a housing 20 with a closed cavity. The multiple battery cells 10 are connected in parallel, series, or mixed configurations and placed inside the housing 20 formed by the interlocking of the first housing 21 and the second housing 22.

[0086] Figure 3 The diagram shown is a structural schematic of a first type of battery cell according to some embodiments of this application.

[0087] like Figure 3As shown, the battery cell 10 includes a housing 11, an electrode assembly 12, a pressure relief component 13, two electrode terminals 14, and two current collectors (not shown in the figure). The housing 11 includes a shell 111 and an end cap 112. The shell 111 includes a side wall 1112 and a bottom wall 1111. The bottom wall 1111 is disposed opposite to the opening 113. The end cap 112 is connected to the side wall 1112 and covers the opening 113. The electrode assembly 12 and the electrolyte are disposed inside the housing 11, and the electrode assembly 12 is immersed in the electrolyte.

[0088] The housing 111 can be hexahedral, cylindrical, or elliptical. The housing 111 can be made of a metallic material, such as aluminum, aluminum alloy, or nickel-plated steel. The end cap 112 is sized and shaped to match the opening 113 of the housing 111, and is fixed to the opening 113, thereby enclosing the electrode assembly 12 and the electrolyte within the receiving cavity of the housing 111. The end cap 112 is made of a metallic material, such as aluminum or steel. The end cap 112 has two electrode lead-out holes, and two electrode terminals 14 are located in these holes. One of the two electrode terminals 14 is a positive electrode terminal, and the other is a negative electrode terminal.

[0089] In some embodiments of this application, the shell 111 extends along a first direction X in its length direction, along a second direction Z in its height direction, and along a third direction Y in its thickness direction. The opening 113 of the shell 111 is disposed opposite to the bottom wall 1111 along the second direction Z. The end cap 112 is rectangular, extending along a first direction X in its length direction, along a third direction Y in its width direction, and along a second direction Z in its thickness direction. The first direction X, the second direction Z, and the third direction Y are perpendicular to each other.

[0090] In other embodiments, the housing 111 may also be a cylinder or elliptical cylinder with its axis extending along the second direction Z, and the size and shape of the end cap 112 may match the opening 113 of the housing 111.

[0091] The electrode assembly 12 includes a main body 121 and two polarity tabs 122, one of which is a positive tab 122 and the other is a negative tab 122. The main body 121 includes a positive electrode plate, a negative electrode plate, and a separator membrane, which is located between the positive and negative electrode plates to separate them. One of the two tabs 122 is the positive tab 122, and the other is the negative tab 122. The positive electrode terminal 14 is electrically connected to the positive tab 122 through a current collector, and the negative electrode terminal 14 is electrically connected to the negative tab 122 through another current collector.

[0092] In some embodiments of this application, the battery cell 10 includes two electrode assemblies 12, which are stacked along a third direction Y. Each electrode assembly 12 includes a body 121 and two tabs 122 of different polarities. The tabs 122 of the same polarity of the two electrode assemblies 12 are connected to a corresponding electrode terminal 14 through the same current collector. In other embodiments, the battery cell 10 may also include only one electrode assembly 12, or include other numbers of electrode assemblies 12 stacked together.

[0093] In some embodiments of this application, the two tabs 122 of different polarities are both located on the side of the body 121 near the end cap 112. In other embodiments, the two tabs 122 of different polarities may be located on both sides of the body 121 along a first direction X, or on the side of the body 121 away from the end cap 112 along a second direction Z; the two tabs 122 of different polarities may also be located on both sides of the body 121 along the second direction Z.

[0094] A pressure relief component 13 is disposed on the housing 11. The pressure relief component 13 is actuated when the internal pressure or temperature of the battery cell 10 reaches a second threshold, so that the internal pressure and temperature of the battery cell 10 can be released. The second threshold can be a temperature threshold or a pressure threshold. The pressure relief component 13 can be disposed on the bottom wall 1111 or the side wall 1112 of the housing 111, or it can be disposed on the end cap 112.

[0095] like Figure 3 As shown, in some embodiments of this application, the end cap 112 has a pressure relief hole 1121 at its center along the first direction X, and the pressure relief component 13 is disposed in the pressure relief hole 1121. Two electrode terminals 14 are respectively disposed on both sides of the pressure relief hole 1121 along the first direction X. In other embodiments, depending on the shape of the battery cell 10, the end cap 112 may also be of other shapes, such as circular or elliptical, and the electrode terminals 14 and the pressure relief component 13 may also be arranged in other ways.

[0096] like Figure 3 As shown, in some embodiments of this application, the battery cell 10 includes a casing 11, a pressure relief component 13, an electrode assembly 12, an electrolyte (not shown in the figure), an encapsulation component 15, and an active material 16 (see reference). Figure 5Electrode assembly 12 is disposed inside housing 11, and electrolyte immerses electrode assembly 12. Pressure relief component 13 is disposed on the first wall of housing 11. Encapsulation component 15 and active material 16 are disposed inside housing 11. Encapsulation component 15 is used to encapsulate active material 16 on the side of electrode assembly 12 near the first wall. Encapsulation component 15 is configured to be actuated to release active material 16 when the internal pressure or temperature of battery cell 10 reaches a first threshold. Active material 16 can react with electrolyte and / or electrode assembly 12 to increase the internal pressure or temperature of battery cell 10, thereby actuating pressure relief component 13.

[0097] The first wall can be located on the side wall 1112 or the bottom wall 1111 of the housing 111, or it can be located on the end cover 112. That is, the pressure relief component 13 can be located on the side wall 1112, the bottom wall 1111, or the end cover 112.

[0098] The first wall is provided with a pressure relief hole 1121, and a pressure relief component 13 is connected to the first wall and covers the pressure relief hole 1121. The pressure relief component 13 can be located in the center of the first wall or near the edge of the first wall. The pressure relief component 13 can be actuated in various ways, such as breaking when the internal pressure of the battery cell 10 reaches a second threshold to release the internal pressure or temperature of the battery cell 10, or melting when the internal temperature of the battery cell 10 reaches a second threshold to release the internal pressure or temperature of the battery cell 10.

[0099] When the encapsulation component 15 is actuated, the active material 16 can be completely released near the pressure relief component 13, or partially released near the pressure relief component 13 and partially released to other locations.

[0100] The encapsulation component 15 can encapsulate the active material 16 in various ways. The encapsulation component 15, together with the first wall, pressure relief component 13, etc., can form a closed space to encapsulate the active material 16. Alternatively, the encapsulation component 15 can have a hollow closed space inside, with the active material 16 encapsulated within it using a composite injection molding method. The active material 16 can completely fill the aforementioned closed space, or it can partially fill it.

[0101] The encapsulation component 15 can be a component independently set up to realize the function of encapsulating the active material 16, or it can be a component inside the battery cell 10 with structural improvements to realize insulation, sealing and other functions so as to have the function of encapsulating the active material 16.

[0102] The actuation of the package 15 can be implemented in various ways, and the first threshold can be a pressure threshold or a temperature threshold. The package 15 can break to release the active material 16 when the internal pressure of the battery cell 10 reaches the first threshold, or it can melt to release the active material 16 when the internal temperature of the battery cell 10 reaches the first threshold.

[0103] The active material 16 can be in liquid, solid, or powder form; the active material 16 can be a substance that reacts chemically with the electrolyte, a substance that reacts chemically with the electrode assembly 12, or a substance that reacts chemically with both the electrolyte and the electrode assembly 12. The active material 16 can be an oxidant, or other substances that can react chemically with the electrolyte and / or the electrode assembly 12 to generate a large amount of high temperature and pressure and break the electrode assembly 12.

[0104] In the battery cell 10 of this application embodiment, an active material 16 is encapsulated near the pressure relief component 13. When thermal runaway occurs at a certain part inside the battery cell 10, the encapsulation component 15 is actuated before the temperature or pressure inside the battery 100 reaches the actuation threshold of the pressure relief component 13, thereby releasing the active material 16. This causes thermal runaway to occur on the side of the electrode assembly 12 closest to the pressure relief component 13, resulting in the electrode assembly breaking down and decomposing, accompanied by the generation of a large amount of high-temperature and high-pressure gas. This causes the temperature or pressure near the pressure relief component 13 to rise rapidly, actuating the pressure relief component 13 to release the pressure or temperature inside the battery cell 10. In particular, when the thermal runaway location of the battery cell 10 is far from the pressure relief component 13, releasing the active material 16 into the battery cell 10 ensures that the pressure relief component 13 is effectively actuated when thermal runaway occurs inside the battery cell 10, smoothly releasing the pressure or temperature inside the battery cell 10, thus giving the battery cell 10 higher safety performance.

[0105] like Figure 3 As shown, in some embodiments of this application, the outer casing 11 includes a housing 111 and an end cap 112. The housing 111 has an opening 113. The housing 111 includes a side wall 1112 and a bottom wall 1111. The bottom wall 1111 is disposed opposite to the opening 113. The end cap 112 is connected to the side wall 1112 and covers the opening 113. The first wall is the end cap 112, the bottom wall 1111, or the side wall 1112.

[0106] Specifically, the bottom wall 1111 and the opening 113 are disposed opposite each other along the second direction Z, the thickness direction of the end cap 112 extends along the second direction Z, and the end cap 112 is connected to the edge of the side wall 1112 away from the bottom wall 1111 and covers the opening 113 to enclose the electrode assembly 12 inside the housing 11.

[0107] It is understandable that the positions of the bottom wall 1111, the side wall 1112, and the end cap 112 are related to the placement of the battery cell 10.

[0108] In some embodiments of this application, the second direction Z extends vertically, the battery cell 10 is placed upright, the first wall is an end cap 112, the pressure relief hole 1121 is arranged upwards, the pressure relief member 13 is located on the upper side of the battery cell 10, and the bottom wall 1111 is located on the bottom side of the battery cell 10. When thermal runaway occurs inside the battery cell 10, the thermal runaway site may be located inside the electrode assembly 12, or it may be close to the surface of the electrode assembly 12; it may be located in the part of the electrode assembly 12 near the bottom wall 1111 or the side wall 1112, or it may be located in the part near the end cap 112. In particular, when thermal runaway occurs at the position of electrode assembly 12 near the bottom wall 1111, the exhaust passage from the side of electrode assembly 12 near the bottom wall 1111 to the pressure relief component 13 is not unobstructed. By actuating the encapsulation component 15 before the pressure relief component 13 is actuated, it is possible to prevent the electrode assembly 12 from being pushed upward under the action of local air pressure. The top of the electrode assembly 12 fits against the end cap 112 to block the pressure relief hole 1121, causing the pressure relief component 13 to be unable to be actuated effectively.

[0109] In other embodiments, depending on the placement of the battery cell 10 and the arrangement of the first wall, the pressure relief hole 1121 can be opened horizontally or set downwards, and the encapsulation 15 can be actuated in advance to release the active material 16, which can ensure that the pressure relief component 13 is effectively actuated.

[0110] In the above scheme, the first wall is an end cap 112, a bottom wall 1111, or a side wall 1112, and the first wall is provided with a pressure relief component 13. When thermal runaway occurs in a certain part inside the battery cell 10, the encapsulation component 15 is actuated before the temperature or pressure inside the battery 100 reaches the actuation threshold of the pressure relief component 13, so as to release the active material 16, causing the part of the electrode assembly 12 near the pressure relief component 13 to break down and decompose under chemical reaction; and the chemical reaction is accompanied by the generation of a large amount of high temperature and high pressure gas, which causes the temperature or pressure near the pressure relief component 13 to rise rapidly, so as to actuate the pressure relief component 13 and release the pressure or temperature inside the battery cell 10.

[0111] In some embodiments of this application, the pressure relief member 13 is configured to be actuated to release pressure when the internal pressure or temperature of the battery cell 10 reaches a second threshold, the second threshold being greater than a first threshold.

[0112] The pressure relief component 13 can be actuated in various ways when the internal pressure of the battery cell 10 reaches the second threshold. The pressure relief component 13 can be a metal sheet with grooves on its surface, or a polymer film with locally thinned sections. When the internal pressure of the battery cell 10 reaches the second threshold, the grooves or the locally thinned sections rupture to release the internal pressure of the battery cell 10. The edge of the pressure relief component 13 can be adhered to the first wall, or it can be pressed tightly against the first wall using a sealing component. When the internal pressure of the battery cell 10 reaches the second threshold, the edge of the pressure relief component 13 separates from the first wall to release the internal pressure of the battery cell 10.

[0113] In other embodiments, the pressure relief element 13 may also be actuated when the internal temperature of the battery cell 10 reaches an actuation threshold, the actuation temperature threshold of the pressure relief element 13 being higher than the internal temperature of the battery cell 10 when the package 15 is actuated.

[0114] Both the pressure relief component 13 and the encapsulation component 15 are actuated by pressure burst, and the actuation threshold of the pressure relief component 13 is greater than that of the encapsulation component 15. This ensures that the encapsulation component 15 is actuated before the pressure relief component 13, so that the pressure inside the battery cell 10 can be released through the pressure relief component 13, thus giving the battery cell 10 better safety performance.

[0115] In some embodiments of this application, the active substance 16 is an oxidant.

[0116] The oxidant can react with the electrolyte and / or the electrodes in the electrode assembly 12 to generate a large amount of high-temperature and high-pressure gas and break the electrodes.

[0117] The oxidant reacts with the electrode assembly 12 and / or the electrolyte. The reaction is rapid and intense, which can break down and decompose the electrode assembly 12 and generate a large amount of high-temperature and high-pressure gas. This ensures the activation of the pressure relief component 13 and allows the pressure or temperature of the thermal runaway part inside the battery cell 10 to be discharged smoothly through the pressure relief component 13.

[0118] In some embodiments of this application, the active substance 16 includes at least one of potassium permanganate, potassium dichromate, sodium hypochlorite, hydrogen peroxide, lead dioxide, periodic acid, cobalt trifluoride, and sodium ferrate.

[0119] The active substance 16 can be a single type of oxidant or a mixture of multiple oxidants. When the active substance 16 is stored separately in different cavities, the active substances 16 in the different cavities can be the same or different.

[0120] The aforementioned active substances 16 do not react with the outer shell 11 and the encapsulation 15, and are common oxidants that are readily available and inexpensive.

[0121] In some embodiments of this application, the encapsulation 15 encapsulates at least a portion of the active material 16 at a position corresponding to the pressure relief member 13.

[0122] The active material 16 can be entirely encapsulated at the position corresponding to the pressure relief component 13; or a portion of the active material 16 can be encapsulated at the position corresponding to the pressure relief component 13 to initiate a chemical reaction in the part of the electrode assembly 12 near the pressure relief component 13, and another portion can be encapsulated at other positions of the electrode assembly 12 near the first wall to initiate a chemical reaction in other positions of the electrode assembly 12 near the first wall.

[0123] The active material 16 not only triggers a chemical reaction near the pressure relief component 13 to actuate the pressure relief component 13, but also triggers a chemical reaction in other locations inside the battery cell 10 to break the corresponding electrode assembly 12, so that the exhaust channel from the thermal runaway part of the battery cell 10 to the pressure relief component 13 is unobstructed, so that the gas generated at the thermal runaway part of the battery cell 10 can be smoothly discharged through the pressure relief component 13.

[0124] Figure 4 What is shown is Figure 3 A schematic diagram of the structure of a single battery cell with an end cap connected to electrode terminals, a pressure relief component, and a packaging component; Figure 5 for Figure 4 AA section view.

[0125] like Figure 4 and Figure 5 As shown, in some embodiments of this application, the outer shell 11 is provided with a pressure relief hole 1121, and the pressure relief component 13 and the encapsulation component 15 both cover the pressure relief hole 1121. The encapsulation component 15 is disposed on the side of the pressure relief component 13 near the electrode assembly 12. The encapsulation component 15, the pressure relief component 13 and the hole wall 11211 of the pressure relief hole 1121 together define a closed space for containing the active material 16.

[0126] like Figure 3 , Figure 4 and Figure 5 As shown, based on the aforementioned embodiment where "the first wall is an end cap 112", the end cap 112 has a first side 1122 and a second side 1123 on both sides along the second direction Z. The first side 1122 is located close to the electrode assembly 12 and inside the battery cell 10, while the second side 1123 is located away from the electrode assembly 12 and outside the battery cell 10. The pressure relief component 13 is located close to the second side 1123, and the encapsulation component 15 is located close to the first side 1122. The pressure relief component 13, the encapsulation component 15, and the wall 11211 of the pressure relief hole 1121 together define a closed space.

[0127] Along the thickness direction of the end cap 112, the pressure relief member 13 is disposed inside the pressure relief hole 1121, the edge of the pressure relief member 13 is connected to the inner wall of the pressure relief hole 1121, and the encapsulation member 15 is located outside the pressure relief hole 1121, and the encapsulation member 15 is connected to the surface of the pressure relief hole 1121 near the first side 1122.

[0128] like Figure 5 As shown, the end cap 112 also includes a first portion 1124 and a second portion 1125. The first portion 1124 protrudes from the hole wall 11211 of the pressure relief hole 1121 onto the surface of the first wall, and the second portion 1125 protrudes from the first side 1122 onto the surface of the first wall. The edge of the pressure relief member 13 is connected to the first portion 1124, and the encapsulation member 15 is connected to the second portion 1125. The first portion 1124, the second portion 1125, the pressure relief member 13, and the encapsulation member 15 together define a closed space 1126.

[0129] In other embodiments, the pressure relief member 13 and the encapsulation member 15 have various ways of covering the pressure relief hole 1121. For example, the pressure relief member 13 and the encapsulation member 15 are connected to the end cap 112 from the first side 1122 and the second side 1123 of the end cap 112 along the second direction Z, respectively; as another example, the pressure relief member 13 is disposed inside the pressure relief hole 1121, the area of ​​the encapsulation member 15 is larger than the area of ​​the pressure relief hole 1121, the encapsulation member 15 covers the pressure relief hole 1121 from the first side 1122 of the end cap 112, and the edge of the encapsulation member 15 is connected to the surface of the end cap 112.

[0130] The active material 16 is encapsulated in the pressure relief hole 1121, which does not occupy too much space inside the battery cell 10, thereby maintaining the original energy density of the battery cell 10; and when the encapsulation component 15 is actuated, the active material 16 is released. The active material 16 can trigger a chemical reaction at the location near the pressure relief hole 1121, which can reliably actuate the pressure relief component 13, so that the battery cell 10 has better safety performance.

[0131] like Figure 5 As shown, in some embodiments of this application, both the pressure relief component 13 and the encapsulation component 15 are sheet-like.

[0132] Both the pressure relief component 13 and the encapsulation component 15 are sheet-shaped, which can occupy a smaller space in the pressure relief hole 1121, thereby providing more space in the pressure relief hole 1121 to store the active material 16.

[0133] Figure 6 The diagram shown is a structural schematic of a second form of battery cell according to some embodiments of this application.

[0134] like Figure 6As shown, in some embodiments of this application, the encapsulation 15 is made of insulating material and is disposed between the first wall and the electrode assembly 12 to insulate and isolate the electrode assembly 12 and the first wall.

[0135] Based on the aforementioned embodiment where "the first wall is the end cap 112", the package is disposed between the end cap 112 and the electrode assembly 12 to insulate and isolate the electrode assembly 12 and the end cap 112.

[0136] The encapsulation component 15 can be a plastic part that melts when the temperature inside the battery 100 reaches a first threshold to release the active material 16; the encapsulation component 15 can also have local weak points that break when the pressure inside the battery 100 reaches a first threshold. The encapsulation component 15 also includes through holes corresponding to the electrode lead-out holes and pressure relief holes 1121 to connect the power supply terminal 14 to the current collector, and the pressure relief hole 1121 communicates with the receiving cavity inside the battery cell 10.

[0137] The encapsulation component 15 is used not only to encapsulate the active material 16, but also to insulate the isolation electrode assembly 12 and the first wall, so that the encapsulation component 15 integrates the insulation function and the function of encapsulating the active material 16, reducing the number of components inside the battery cell 10, making the battery cell 10 compact and having a high energy density.

[0138] Figure 7 What is shown is Figure 6 A schematic diagram of the structure of a battery cell with an end cap connected to electrode terminals, a pressure relief component, and a packaging component; Figure 8 for Figure 7 BB cross-section diagram.

[0139] like Figure 7 and Figure 8 As shown, in some embodiments of this application, the encapsulation 15 has a first receiving cavity 1512 corresponding to the position of the pressure relief member 13, and at least a portion of the active material 16 is encapsulated in the first receiving cavity 1512.

[0140] The active material 16 can be completely encapsulated in the first receiving cavity 1512, or it can be partially encapsulated in the first receiving cavity 1512 and the remainder encapsulated in other locations.

[0141] The first receiving cavity 1512 can be formed by the encapsulation 15 together with other components, or it can exist independently inside the encapsulation 15.

[0142] The projection of the pressure relief hole 1121 on the XY plane can fall into the projection of the first receiving cavity 1512 on the XY plane, so that the active material 16 released in the first receiving cavity 1512 can trigger a chemical reaction in a large area near the pressure relief component 13, rapidly generating a large amount of gas to actuate the pressure relief component 13; alternatively, the projection of the first receiving cavity 1512 on the XY plane can fall into the projection of the pressure relief hole 1121 on the XY plane, or the projection of the first receiving cavity 1512 on the XY plane can partially overlap with the projection of the pressure relief hole 1121 on the XY plane, so that the storage position of the active material 16 can be flexibly arranged according to the internal space of the battery cell 10, as long as the large amount of gas generated by the chemical reaction triggered by the active material 16 when the encapsulation component 15 is actuated can actuate the pressure relief component 13.

[0143] When the encapsulation component 15 is actuated, it can release the active material 16 in the first receiving cavity 1512, triggering a chemical reaction near the pressure relief component 13, which can reliably actuate the pressure relief component 13, giving the battery cell 10 better safety performance.

[0144] Figure 9 for Figure 8 A magnified view of a section at point C. Figure 9 It shows Figure 6 A schematic diagram of the structure of the first type of first receiving cavity of the battery cell.

[0145] like Figure 9 As shown, in some embodiments of this application, the first receiving cavity 1512 has a first opening, and the first wall and the pressure relief member 13 together close the first opening.

[0146] Based on the implementation of "the first wall is the end cap 112", a first groove 151 is provided at the center of the package 15 along the first direction X. The first groove 151 is formed by the surface of the package 15 being recessed in the direction away from the end cap 112. The interior of the first groove 151 has a first receiving cavity 1512. The opening 113 on the side of the first groove 151 near the end cap 112 constitutes the first opening. The projection of the pressure relief member 13 in the XY plane falls into the projection of the first groove 151 in the XY plane. The first side 1122 of the end cap 112 fits against the package 15 and closes the first opening, forming a closed first receiving cavity 1512.

[0147] Figure 10 What is shown is Figure 6 A schematic diagram of the first accommodating cavity in the second form of a single battery cell.

[0148] like Figure 10As shown, specifically, the middle portion of the first groove 151 is further recessed towards the direction away from the end cap 112 to form a storage portion 1513. The storage portion 1513 is used to store active material 16, so that more active material 16 is stored in the vicinity of the pressure relief member 13. The projection of the storage portion 1513 on the XY plane falls into the projection of the pressure relief member 13 on the XY plane. When the package 15 is actuated, it can preferentially trigger a chemical reaction in the part near the pressure relief member 13, thereby increasing the speed of actuation of the pressure relief member 13. The side of the storage portion away from the end cap 112 can be used to abut against the surface of the electrode assembly 12, so that both sides of the package 15 abut against the end cap 112 and the electrode assembly 12, making the battery cell 10 structure compact.

[0149] Figure 11 What is shown is Figure 6 A schematic diagram of the structure of the first receiving cavity in the third form of the battery cell packaging; Figure 12 What is shown is Figure 11 A schematic diagram of the packaging components.

[0150] like Figure 11 and Figure 12 As shown, in other embodiments, the first receiving cavity 1512 can also be a closed space independently formed inside the package 15, with the active material 16 encapsulated inside the first receiving cavity 1512 by composite injection molding. Specifically, the package 15 has a support portion 154 at the through-hole corresponding to the pressure relief hole 1121. The support portion 154 blocks part of the through-hole and exposes the spaces on both sides of the through-hole along the first direction X, forming two venting spaces 155. One side of the support portion 154 abuts against the pressure relief member 13, so that the two venting spaces 155 communicate with the interior of the battery cell 10. The support portion 154 and the storage portion 1513 of the first groove 151 together enclose the closed first receiving cavity 1512, and the active material 16 is encapsulated inside the first receiving cavity 1512.

[0151] The first wall, the pressure relief component 13, and the encapsulation component 15 together form a closed first receiving cavity 1512, which not only encapsulates the active material 16 near the pressure relief component 13, but also allows the active material 16 to initiate a chemical reaction near the pressure relief component 13 when it is released, and makes it easy to encapsulate the active material 16.

[0152] Figure 13 for Figure 8 A magnified view of a section at point D.

[0153] like Figure 8 and Figure 13As shown, in some embodiments of this application, the first wall is rectangular, and the package 15 also has two second receiving cavities 1522. Along the length direction of the first wall, the two second receiving cavities 1522 are located on both sides of the first receiving cavity 1512. A portion of the active material 16 is packaged in the first receiving cavity 1512, and the other portion is packaged in the two second receiving cavities 1522.

[0154] Based on the embodiment where "the first wall is the end cap 112", the end cap 112 is a rectangle extending along the first direction X in the length direction and along the third direction Y in the width direction. Along the first direction, each end of the package 15 has a second receiving cavity 1522. The second receiving cavity 1522 can be a closed space independently formed inside the package 15, and the active material 16 is encapsulated inside the second receiving cavity 1522 by composite injection molding; the second receiving cavity 1522 can also be a closed space formed by the package 15 and the end cap 112 together.

[0155] Along the length of the first wall, a second receiving cavity 1522 is provided on each side of the first receiving cavity 1512. The second receiving cavity 1522 contains a portion of active material 16. When the active material 16 in the second receiving cavity 1522 is released, it can trigger a chemical reaction at the corresponding position of the electrode assembly 12, so that the side of the electrode assembly 12 near the pressure relief component 13 is fully broken, and the exhaust channel from the thermal runaway part of the battery cell 10 to the pressure relief component 13 remains unobstructed.

[0156] like Figure 13 As shown, in some embodiments of this application, the second receiving cavity 1522 has a second opening, and the first wall closes the second opening.

[0157] Specifically, along the first direction, each end of the package 15 has a second groove 152. The second groove 152 is formed by recessing from the surface of the package 15 in a direction away from the end cap 112. The interior of the second groove 152 has a second receiving cavity 1522. The opening 113 of the second groove 152 near the end cap 112 constitutes a second opening. The package 15 is fitted to the end cap 112 to close the second opening, forming a closed second receiving cavity 1522.

[0158] The second receiving cavity 1522 can be the same size as the electrode assembly 12 along the third direction Y, so that the end corners of the electrode assembly 12 on the side near the end cap 112 break apart, so that the exhaust passage from the thermal runaway part of the electrode assembly 12 to the pressure relief component 13 is unobstructed; the second receiving cavity 1522 can also be centrally located relative to the electrode assembly 12 along the third direction Y.

[0159] Specifically, the package 15 has connecting portions 153 that abut against the surface of the electrode assembly 12 on both sides along the first direction X. The connecting portions 153 are formed by protruding from the side of the package 15 away from the end cap 112 along the second direction Z. The second groove 152 is formed inside the connecting portion to make the package 15 have a compact structure.

[0160] The first wall and the encapsulation 15 together form a closed second receiving cavity 1522. When the active material 16 is released, it can trigger a chemical reaction at the corresponding position, and the encapsulation of the active material 16 is easy to achieve.

[0161] Some embodiments of this application provide a battery 100, including a battery cell 10 according to some embodiments of this application.

[0162] Due to the characteristics of the battery cell 10, the battery 100 in some embodiments of this application also has good safety performance.

[0163] Some embodiments of this application provide an electrical device including a battery 100.

[0164] Due to the characteristics of the battery 100, the electrical devices in some embodiments of this application also have good safety performance.

[0165] Some embodiments of this application provide a method for manufacturing a battery cell 10, including:

[0166] A housing 11 is provided, and a pressure relief element 13 is provided on the first wall of the housing 11;

[0167] Provide electrode assembly 12;

[0168] Provide electrolyte;

[0169] An encapsulation 15 and an active material 16 are provided. The encapsulation 15 is used to encapsulate the active material 16. The encapsulation 15 is configured to be actuated to release the active material 16 when the internal pressure or temperature of the battery cell 10 reaches a first threshold. The active material 16 is capable of reacting with the electrolyte and / or electrode assembly 12 to increase the internal pressure or temperature of the battery cell 10, thereby actuating the pressure relief component 13.

[0170] The electrode assembly 12 is placed inside the housing 11, and the active material 16 is encapsulated in the side of the electrode assembly 12 near the first wall using the encapsulation component 15. The electrolyte is then injected into the housing 11.

[0171] Some embodiments of this application provide a manufacturing apparatus for a battery cell 10, comprising:

[0172] A first supplying device is used to supply a housing 11, the first wall of which is provided with a pressure relief element 13;

[0173] A second supplying device is used to supply electrode assembly 12;

[0174] The third supply device is used to supply electrolyte;

[0175] The fourth providing device is used to provide a package 15 and an active material 16. The package 15 is used to encapsulate the active material 16. The package 15 is configured to be actuated to release the active material 16 when the internal pressure or temperature of the battery cell 10 reaches a first threshold. The active material 16 is capable of reacting with the electrolyte and / or electrode assembly 12 to increase the internal pressure or temperature of the battery cell 10, thereby actuating the pressure relief device 13.

[0176] The mounting module is used to place the electrode assembly 12 inside the housing 11, encapsulate the active material 16 in the side of the electrode assembly 12 near the first wall with the encapsulation component 15, and inject the electrolyte into the housing 11.

[0177] like Figures 3 to 5 As shown, some embodiments of this application propose a battery cell 10, which includes a housing 111, an end cap 112, an electrode assembly 12, a pressure relief component 13, and an encapsulation component 15. The end cap 112 has a pressure relief hole 1121, and an explosion-proof sheet with an upper and lower layer structure is provided at the pressure relief hole 1121. The upper explosion-proof sheet is the pressure relief component 13, and the lower explosion-proof sheet is the encapsulation component 15. The explosion-proof sheet is generally made of metal, such as aluminum or steel, but can also be made of plastic. An active material 16 is added between the upper and lower explosion-proof sheets. The active material 16 is generally a strong oxidant, such as potassium permanganate, potassium dichromate, sodium hypochlorite, hydrogen peroxide, lead dioxide, periodic acid, cobalt trifluoride, sodium ferrate, etc. When thermal runaway occurs inside the battery cell and gas is slowly generated, the internal gas pressure reaches the first threshold, which is lower than the opening pressure of the upper explosion-proof sheet. The gas pressure inside the battery cell will force open the lower explosion-proof sheet, releasing the active material 16 to react with the electrolyte. This causes the electrode assembly near the pressure relief component 13 to fail, generating a large amount of high-temperature and high-pressure gas. This gas then further breaks through the upper explosion-proof sheet, releasing heat and ejecting broken and decomposed electrode pieces. This increases the exhaust gap at the pressure relief hole 1121, allowing the failed electrode pieces to be smoothly discharged when the electrode assembly far from the pressure relief hole 1121 fails. This prevents the electrode assembly 12 from rushing upwards due to the failure of the pressure relief component 13, which could cause the battery cell 10 to explode and result in a serious safety accident.

[0178] like Figures 6 to 13As shown, some embodiments of this application propose a battery cell 10, which includes a housing 111, an end cap 112, an electrode assembly 12, a pressure relief component 13, and an encapsulation component 15. The end cap 112 is provided with the pressure relief component 13. The encapsulation component 15 is made of lower plastic and is disposed between the end cap 112 and the electrode assembly 12. Along the length direction of the end cap 112 (i.e., the first direction X), the length of the encapsulation component 15 is approximately the same as the length of the electrode assembly 12. The encapsulation component 15 has semi-open grooves in the middle and at both ends. The encapsulation component 15 fits against the end cap 112 to encapsulate the active material 16 inside the grooves. When the internal gas of the battery cell 10 generates high temperature, the lower plastic melts, releasing the active material 16 to react with the electrode assembly, expelling the electrode plates closer to the pressure relief hole 1121, creating an exhaust gap, and preventing the end cap 112 from bursting open from the housing 111.

[0179] It should be noted that, where there is no conflict, the features in the embodiments of this application can be combined with each other.

[0180] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery cell, characterized in that, include: shell; Pressure relief components are disposed on the first wall of the housing; The electrode assembly is disposed inside the housing; The electrode assembly is immersed in electrolyte. An encapsulation component and an active material are disposed inside the housing. The encapsulation component is used to encapsulate the active material on the side of the electrode assembly near the first wall. The encapsulation component is configured to be actuated to release the active material when the internal pressure or temperature of the battery cell reaches a first threshold. The active material is capable of reacting with the electrolyte and / or the electrode assembly to increase the internal pressure or temperature of the battery cell, thereby actuating the pressure relief component. The encapsulation component is made of insulating material and is disposed between the first wall and the electrode assembly to insulate and isolate the electrode assembly and the first wall. The encapsulation has a first receiving cavity corresponding to the position of the pressure relief component, and at least a portion of the active material is encapsulated in the first receiving cavity; The first receiving cavity has a first opening, and the first wall and the pressure relief member together close the first opening.

2. The battery cell according to claim 1, characterized in that, The pressure relief device is configured to be actuated to release pressure when the internal pressure or temperature of the battery cell reaches a second threshold, the second threshold being greater than the first threshold.

3. The battery cell according to claim 1, characterized in that, The active substance is an oxidant.

4. The battery cell according to claim 3, characterized in that, The active substance includes at least one of potassium permanganate, potassium dichromate, sodium hypochlorite, hydrogen peroxide, lead dioxide, periodic acid, cobalt trifluoride, and sodium ferrate.

5. The battery cell according to claim 1, characterized in that, The outer shell is provided with a pressure relief hole, and the pressure relief component and the encapsulation component both cover the pressure relief hole. The encapsulation component is disposed on the side of the pressure relief component near the electrode assembly. The encapsulation component, the pressure relief component, and the hole wall of the pressure relief hole together define a closed space for containing the active material.

6. The battery cell according to claim 5, characterized in that, Both the pressure relief component and the encapsulation component are sheet-like.

7. The battery cell according to claim 1, characterized in that, The first wall is rectangular, and the package also has two second receiving cavities, which are located on both sides of the first receiving cavity along the length of the first wall. A portion of the active material is encapsulated in the first containment cavity, and the other portion is encapsulated in the two second containment cavities.

8. The battery cell according to claim 7, characterized in that, The second receiving cavity has a second opening, which is closed by the first wall.

9. The battery cell according to any one of claims 1-8, characterized in that, The housing includes a shell and an end cap. The shell has an opening. The shell includes a side wall and a bottom wall. The bottom wall is disposed opposite to the opening. The end cap is connected to the side wall and covers the opening. The first wall is the end cap, the bottom wall, or the side wall.

10. A battery, characterized in that, Includes the battery cell as described in any one of claims 1-9.

11. An electrical appliance, characterized in that, Includes the battery as described in claim 10.

12. A method for manufacturing a single battery cell, characterized in that, include: A housing is provided, wherein a pressure relief element is provided on the first wall of the housing; Provide electrode assemblies; Provide electrolyte; An encapsulation and an active material are provided. The encapsulation is used to encapsulate the active material and is configured to be actuated to release the active material when the internal pressure or temperature of the battery cell reaches a first threshold. The active material is capable of reacting with the electrolyte and / or the electrode assembly to increase the internal pressure or temperature of the battery cell, thereby actuating the pressure relief device. The encapsulation is made of an insulating material. The electrode assembly is disposed within the housing. The active material is encapsulated in the side of the electrode assembly near the first wall using the encapsulation member. The encapsulation member is disposed between the first wall and the electrode assembly to insulate and isolate the electrode assembly and the first wall. The encapsulation member has a first receiving cavity corresponding to the position of the pressure relief member. At least a portion of the active material is encapsulated in the first receiving cavity. The first receiving cavity has a first opening. The first wall and the pressure relief member together close the first opening. The electrolyte is then injected into the housing.

13. A manufacturing apparatus for a single battery cell, characterized in that, include: A first providing device is used to provide a housing, the first wall of which is provided with a pressure relief element; A second providing device is used to provide electrode assemblies; The third supply device is used to supply electrolyte; A fourth providing device is used to provide an encapsulation and an active material, the encapsulation being used to encapsulate the active material, the encapsulation being configured to be actuated to release the active material when the internal pressure or temperature of the battery cell reaches a first threshold, the active material being capable of reacting with the electrolyte and / or the electrode assembly to increase the internal pressure or temperature of the battery cell, thereby actuating the pressure relief device, the encapsulation being made of an insulating material; The mounting module is used to place the electrode assembly inside the housing, and to encapsulate the active material in the side of the electrode assembly near the first wall using the encapsulation member. The encapsulation member is disposed between the first wall and the electrode assembly to insulate and isolate the electrode assembly and the first wall. The encapsulation member has a first receiving cavity corresponding to the position of the pressure relief member. At least a portion of the active material is encapsulated in the first receiving cavity. The first receiving cavity has a first opening. The first wall and the pressure relief member together close the first opening, and the electrolyte is injected into the housing.

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