A single battery, a manufacturing method thereof, a battery pack, and an electric device

Abstract

This application discloses a single-cell battery, its manufacturing method, battery pack, and electrical device. The single-cell battery has an explosion-proof valve on a first side of the casing, and a thermally responsive deformation element is provided between a predetermined area on the inner wall of the first side and the core assembly. When the temperature of the thermally responsive deformation element is greater than or equal to the trigger temperature, the element deforms and supports the core assembly to move away from the predetermined area, thereby lifting the core assembly and forming a stable and effective air passage between the core assembly near the explosion-proof valve and the inner wall of the casing. This prevents the core assembly from blocking the explosion-proof valve, affecting venting, and causing problems such as battery casing explosion.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a single cell battery and its manufacturing method, as well as a battery pack and electrical device incorporating the single cell battery. Background Technology

[0002] A single cell refers to the most basic and indivisible independent energy storage unit in an electrochemical energy storage device. It is the smallest functional unit that makes up all battery packs or battery arrays.

[0003] With the widespread application of high-energy-density batteries in electric vehicles, mobile devices, and other fields, their safety has become an increasingly important concern. Developing safety technologies that do not affect the battery's energy density, electrical performance, or manufacturing efficiency while maintaining battery safety is a significant challenge. In particular, when a single battery experiences thermal runaway, its internal core components rapidly generate gas. Especially when the explosion-proof valve is venting downwards, the core components can easily block the pressure relief port, causing the casing to deform or rupture. This prevents thermoelectric separation and ultimately leads to thermal diffusion of the battery pack, posing a serious safety hazard. Summary of the Invention

[0004] In view of this, the purpose of this application is to provide a single cell battery and its manufacturing method, as well as a battery pack and electrical device, which can avoid the safety hazards caused by the core assembly blocking the pressure relief port and causing the exhaust to be blocked when the battery thermal runaway occurs.

[0005] To achieve the above objectives, this application provides the following technical solution: A single battery cell includes a housing and an electrode core assembly and a thermally responsive deformation element located within the housing. An explosion-proof valve is provided on a first side of the housing, and the thermally responsive deformation element is located between a predetermined area on the inner wall of the first side and the electrode core assembly. When the temperature of the thermally responsive deformation element is lower than the trigger temperature: the thermally responsive deformation element maintains a first state; in the direction perpendicular to the first side, the gap distance between the preset area and the pole core assembly is a first gap distance d1; the trigger temperature is any value within the range of 105℃ to 250℃; When the temperature of the thermally responsive deformation element is greater than or equal to the trigger temperature: the thermally responsive deformation element deforms into a second state and supports the pole core assembly to move away from the preset area; in the direction perpendicular to the first side, the gap distance between the preset area and the pole core assembly is a second gap distance d2, where d2 > d1.

[0006] Optionally, in the above-mentioned single cell, the first side is the bottom surface of the casing, and the thermally responsive deformation element is located between the bottom of the electrode core assembly and the first side. In the direction perpendicular to the first side, the thickness T of the thermally responsive deformation component before deformation satisfies the condition: T>(G+2×P×L'×H'×μ) / δ / C; G is the gravity of the core assembly; P is the restraint pressure of the core assembly; L' is the length of the core assembly in the horizontal direction, and the core assembly has restraint pressure on both sides of its horizontal surface. H' is the height dimension of the pole core assembly in the vertical direction; μ is the coefficient of friction between the two horizontal surfaces of the core assembly and the inner wall of the housing. δ represents the recovery stress of the thermally responsive deformation component after deformation; C is the side length dimension of the thermally responsive deformation component when it is in the second state and has not deformed.

[0007] Optionally, in the above-mentioned single cell, the thickness T of the thermally responsive deformation element before deformation satisfies the condition: T≤H 余 1mm≤H 余 ≤3mm; H 余 This refers to the single-sided margin by which the diaphragm width in the core assembly exceeds the width of the negative electrode sheet in a direction perpendicular to the first side.

[0008] Optionally, in the above-mentioned single cell, the thickness T of the thermally responsive deformation element before deformation in the direction perpendicular to the first side is any value within the range of 0.1 mm to 0.6 mm.

[0009] Optionally, in the above-mentioned single cell, the trigger temperature is any value within the range of 130°C to 200°C.

[0010] Optionally, in the above-described single battery cell, in the direction perpendicular to the first side, the inner cavity height of the casing is H, and the height of the electrode core assembly is H', wherein: d1=(H-H') / 2, d1<d2<H-H'.

[0011] Optionally, in the above-mentioned single cell, the thermally responsive deformation component is a planar sheet structure parallel to the preset area before deformation; the planar sheet structure is a solid plate, or the planar sheet structure is a hollow plate with at least one vent hole or vent groove. The thermally responsive deformation component deforms into an arc-shaped curved surface structure, with its arc-shaped opening facing the preset area or the pole core assembly.

[0012] Optionally, in the above-mentioned single cell, the material of the thermally responsive deformation element is a shape memory alloy; Alternatively, the surface of the thermally responsive deformation component is provided with an encapsulating adhesive layer; Alternatively, the thermally responsive deformation element comprises a metal spring layer and a hot-melt shaping layer: When the temperature of the thermally responsive deformation component is lower than the trigger temperature, the hot-melt shaping layer is solid, and under the action of the self-stiffness of the hot-melt shaping layer, the metal spring sheet layer maintains the first state; When the temperature of the thermally responsive deformation element is greater than or equal to the trigger temperature, the hot-melt shaping layer melts into a liquid state, and the metal spring sheet layer deforms into the second state under its own elastic action.

[0013] Optionally, in the above-mentioned single battery cell, the thermally responsive deformation element is provided on the side of the explosion-proof valve that is farther away from the second side of the housing in the vertical direction, or at least one thermally responsive deformation element is provided on each side of the explosion-proof valve.

[0014] Optionally, in the above-mentioned single cell, the electrode core assembly includes an electrode core body composed of electrode sheets and separators stacked and arranged, and an insulating film wrapped around the electrode core body, wherein the thermally responsive deformation element is composited on the insulating film.

[0015] Optionally, in the above-mentioned single cell, the thermally responsive deformation element is attached to the preset area before deformation.

[0016] Optionally, in the above-mentioned single cell, the thermally responsive deformation element is located on the side of the insulating film closer to the preset region; or, the thermally responsive deformation element is located on the side of the insulating film away from the preset region; or, the thermally responsive deformation element is located between the two layers of the insulating film.

[0017] Optionally, in the above-mentioned single cell, the thermally responsive deformation element is laminated onto the insulating film by means of bonding and / or hot-melt encapsulation; Alternatively, the thermally responsive deformation element may be attached to a predetermined area on the inner wall of the first side.

[0018] Optionally, in the above-mentioned single cell, the single cell includes a blade cell.

[0019] A method for manufacturing a single cell as described above, the method comprising: S1: Select the material of the thermally responsive deformation component according to the temperature at which the single cell experiences thermal runaway, wherein the trigger temperature of the material is within the temperature range at which the single cell experiences thermal runaway; S2: Determine the phase transformation recovery stress δ of the thermally responsive deformation component based on the selected material; S3: Confirm the gravity G of the core component; S4: Calculate the frictional resistance F between the core assembly and the inner wall of the housing. 摩 F 摩 = F 压 ×μ=2×P×S×μ=2×P×L'×H'×μ; F 压 The pressure exerted by the core assembly on the housing; μ is the coefficient of friction between the two horizontal surfaces of the core assembly and the inner wall of the housing. P is the restraint pressure of the core assembly; S is the contact area between the core assembly 2 and a single inner side of the housing 1; L' is the length of the core assembly in the horizontal direction, and the core assembly has restraint pressure on both sides of its horizontal surface. H' is the height dimension of the pole core assembly in the vertical direction; S5: Calculate the supporting force F after the thermally responsive deformation component deforms. 支 F 支 =S 截 ×δ,S 截 The cross-sectional area of ​​the thermally responsive deformable component at any deformation location within a section perpendicular to the deformation direction; S6: Calculate the thickness T of the thermally responsive deformation component in the first state with a sheet-like structure, wherein the thickness T satisfies the condition T>(G+2×P×L'×H'×μ) / δ / C; G is the gravity of the core assembly; δ represents the recovery stress of the thermally responsive deformation component after deformation; C is the side length dimension of the thermally responsive deformation component when it is in the second state and has not deformed; S7: The thermally responsive deformable part with a curved structure in the second state is processed and manufactured, and its bulge height T' satisfies: T' < H - H'; In a direction perpendicular to the first side, the inner cavity height of the housing is H, and the height of the pole core assembly is H'; S8: Process and manufacture the thermally responsive deformation component that has a sheet-like structure in the first state.

[0020] Optionally, the above manufacturing method further includes: S9: Immerse the thermally responsive deformable part, which has a sheet-like structure in the first state, into the adhesive liquid, and after drying, form an encapsulating adhesive layer on the surface of the thermally responsive deformable part.

[0021] A battery pack includes a plurality of individual cells arranged side by side, at least some of which are the individual cells described above.

[0022] An electrical device includes a battery system in which a battery pack as described above is disposed.

[0023] As can be seen from the above technical solutions, in the single cell, battery pack and electrical device provided in this application, since a thermally responsive deformation element is provided between the core assembly and the inner wall of the casing, the thermally responsive deformation element can quickly respond and deform when the single cell experiences thermal runaway, thereby lifting the core assembly and forming a stable and effective air passage between the core assembly near the explosion-proof valve and the inner wall of the casing, preventing the core assembly from blocking the explosion-proof valve and affecting the exhaust, which could lead to problems such as battery casing explosion.

[0024] Furthermore, this application also provides a manufacturing method applicable to the above-mentioned single cell, which designs and manufactures the thermally responsive deformation component based on the characteristics of the battery itself. This method can solve the problem of thermal runaway and casing explosion of single cells with explosion-proof valves at the bottom, while reducing the space occupied by the thermally responsive deformation component in the single cell, without losing battery performance or affecting the performance of the cell, and with virtually no loss of the energy density of the single cell. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the structure of a single battery provided in an embodiment of this application, in which a thermally responsive deformation element at the bottom of the electrode core assembly is in a first state.

[0027] Figure 2 This is a schematic diagram of the structure of a single battery provided in an embodiment of this application, in which a thermally responsive deformation element at the bottom of the electrode core assembly is in a second state.

[0028] Figure 3 for Figure 2 A side view of a single cell in the image.

[0029] Figure 4 An isometric view of a thermally responsive deformation component in a first state, provided as an embodiment of this application.

[0030] Figure 5 for Figure 4 A top view of the thermally responsive deformation component.

[0031] Figure 6 for Figure 4 The front view of the thermally responsive deformation component.

[0032] Figure 7 for Figure 6 A schematic diagram of the structure of the thermally responsive deformation component in the second state.

[0033] Figure 8 An isometric view of a thermally responsive deformation component in a second state, provided as an embodiment of this application.

[0034] Figure 9 An isometric view of another thermally responsive deformation component in a second state, provided in an embodiment of this application.

[0035] Figure 10 This is a schematic diagram of the mounting structure of a thermally responsive deformation element in a blade battery in a first state, provided in an embodiment of this application.

[0036] Figure 11 A schematic diagram of the installation structure of a thermally responsive deformation element in the second state of a blade battery provided in this application embodiment (arc-shaped opening facing upward).

[0037] Figure 12 This is a schematic diagram of the installation structure of a thermally responsive deformation element in a blade battery in the second state, provided in an embodiment of this application (arc-shaped opening facing downwards).

[0038] Figure 13 This is a schematic diagram of the structure of a single battery cell provided in another embodiment of this application, wherein the two thermally responsive deformation elements at the bottom of the core assembly are in a first state.

[0039] Figure 14 This is a schematic diagram of the structure of a single cell provided in another embodiment of this application, in which two thermally responsive deformation elements at the bottom of the core assembly are in a second state.

[0040] in: 1-Shell, 2-Electrode core assembly, 3-Explosion-proof valve, 4-Thermal response deformation component, 11-First side surface, 12-Second side surface, 21-Negative electrode sheet, 22-Separator, 40-Groove. Detailed Implementation

[0041] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and 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.

[0042] Please see Figure 1 and Figure 2This application provides a single-cell battery, which includes a casing 1 and a core assembly 2. The core assembly 2 is located inside the casing 1, and at least one side of the casing 1 (e.g., the first side 11) is provided with an explosion-proof valve 3. When the internal pressure of the battery reaches a preset value, the weak structure of the explosion-proof valve 3 is ruptured / torn, quickly releasing the high-pressure gas and part of the electrolyte inside the battery, avoiding safety hazards such as battery bulging, rupture, or even fire and explosion. Furthermore, the single-cell battery also includes a thermally responsive deformation element 4, located between a preset area on the inner wall of the casing side (e.g., the first side 11) where the explosion-proof valve 3 is located and the core assembly 2. The thermally responsive deformation element 4 and the explosion-proof valve 3 are located on the same side of the core assembly 2. The area on the inner wall of the casing 1 corresponding to the thermally responsive deformation element 4 is called the preset area, meaning the thermally responsive deformation element 4 is located between the preset area on the inner wall of the casing 1 and the core assembly 2. The following is a specific example of a first side 11 located at the bottom of the housing 1 with an explosion-proof valve 3 and a thermally responsive deformation element 4 disposed between the first side 11 and the core assembly 2.

[0043] When the temperature of the thermally responsive deformation element 4 is lower than the trigger temperature: the thermally responsive deformation element 4 remains in the first state. At this time, in the direction perpendicular to the first side 11 (which is also parallel to the exhaust direction of the explosion-proof valve 3), the gap distance between the preset area in the inner wall of the housing 1 that is in contact with the thermally responsive deformation element 4 (or the preset area in the inner wall of the housing 1 that is covered by the thermally responsive deformation element 4) and the pole core assembly 2 is the first gap distance d1. Figure 1 As shown; When the temperature of the thermally responsive deformation element 4 is greater than or equal to the trigger temperature: the thermally responsive deformation element 4 deforms into a second state, thereby supporting the core assembly 2 to move away from the aforementioned preset area; in the direction perpendicular to the first side 11, the gap distance between the aforementioned preset area and the core assembly 2 is the second gap distance d2, d2 > d1, as shown. Figure 2 As shown in the image.

[0044] It should be noted that the trigger temperature mentioned in this application refers to the temperature at which the thermal response deformation component 4 is triggered to deform, which is also the temperature at which a single cell experiences thermal runaway. It is generally any value within the range of 105℃ to 250℃, such as 105℃, 110℃, 115℃, 120℃, 125℃, 130℃, 135℃, 140℃, 145℃, 150℃, 155℃, 160℃, 165℃, 170℃, 175℃, 180℃, 185℃, 190℃, 195℃, 200℃, 205℃, 210℃, 215℃, 220℃, 225℃, 230℃, 235℃, 240℃, 245℃, and 250℃. Preferably, the trigger temperature can be any value within the range of 130°C to 200°C, such as 130°C, 135°C, 140°C, 145°C, 150°C, 155°C, 160°C, 165°C, 170°C, 175°C, 180°C, 185°C, 190°C, 195°C, and 200°C.

[0045] It is evident that when a single cell experiences thermal runaway, the increased temperature can trigger the thermal response deformation component 4 located within the single cell to rapidly deform, thereby lifting the core assembly 2. This creates a stable and effective air passage between the core assembly 2 near the explosion-proof valve 3 and the inner wall of the casing 1, preventing the core assembly 2 from blocking the explosion-proof valve 3 and affecting the exhaust, which could lead to problems such as battery casing explosion.

[0046] Considering that when the thickness of the thermally responsive deformation element 4 is small, its supporting strength is weak, making it impossible to achieve an effective air passage; and when the thickness of the thermally responsive deformation element 4 is large, the separation gap between the core assembly 2 and the casing 1 at the bottom of the battery is too large, resulting in electrolyte residue at the bottom of the casing and insufficient wetting of the core assembly 2 in the electrolyte. This reduces the battery's cycle life during long-term use, and also reduces the overall volumetric energy density of the battery when the thickness of the thermally responsive deformation element 4 is large. Therefore, the thermally responsive deformation element 4 provided in this application is designed and manufactured based on the battery's own characteristics.

[0047] Please see details. Figures 4 to 9 In some embodiments, before deformation, the thermally responsive deformation element 4 has a long side length of A, a short side length of B, and a thickness of T. The length of the deformed side can be either A or B. The phase transformation recovery stress of the thermally responsive deformation element 4 is δ, the cross-sectional area is S_section, the bulge height is T', and the supporting force is F_support. The frictional force and friction coefficient between the two side surfaces of the core assembly 2 and the inner wall of the housing 1 are F_friction and μ, respectively, and the pressure of the core assembly 2 on the housing 1 is F_pressure. Furthermore, please refer to... Figures 1 to 3The inner cavity of shell 1 has a length of L, a width of W, and a height of H; the core assembly 2 has a length of L', a thickness of W', and a height of H' (which can be calculated from the width of the negative electrode sheet); the diaphragm width exceeds the width of the negative electrode sheet by a single-sided margin of H_surplus; the mass of core assembly 2 is m, its gravity is G=mg (g is the gravitational acceleration constant, usually taken as g≈9.8m / s²), its volumetric energy density is ρ, and its constraint pressure is P (the design value can be any value within the range of 0 to 10 kPa, such as 0 kPa, 0.1 kPa, 0.5 kPa, 0.75 kPa, 1.0 kPa, 1.5 kPa, 2.0 kPa, 2.5 kPa, 3.0 kPa, 3.5 kPa, 4.0 kPa, 5 kPa). (0kPa, 6.0kPa, 7.0kPa, 7.5kPa, 8.0kPa, 8.5kPa, 9.0kPa, 9.5kPa, 9.9kPa, 10kPa), the contact area between the core assembly 2 and a single inner side of the housing 1 is S. Generally, the upper limit Tmax of the thickness of the thermally responsive deformable element 4 depends on the single-sided allowance H_remaining of the diaphragm super-negative electrode sheet in the core assembly 2. Its design value is generally any value within the range of 1mm to 3mm, such as 1.0mm, 1.1mm, 1.2mm, 1.5mm, 1.75mm, 1.8mm, 1.9mm, 2.0mm, 2.1mm, 2.5mm, 2.75mm, 2.9mm, and 3.0mm, ensuring that the diaphragm can adsorb the electrolyte. The lower limit Tmin of the thickness of the thermally responsive deformable element 4 depends on parameters such as the gravity of the core assembly 2, the frictional force F_friction between the core assembly 2 and the shell 1, the recovery stress δ, and the deformation cross-sectional area, ensuring that the deformation force can overcome gravity and frictional resistance. Therefore, after the thermally responsive deformable element 4 deforms: If the thermally responsive deformation component 4 gradually bends along the extension direction of its long side (e.g.) Figure 8 If ), then S 截 =B×T, Tmax=H_remainder>T>(G+ 2×P×L'×H'× μ) / δ / B=Tmin, at this time, B is the side length dimension C that has not been deformed, that is, Tmax=H_remainder>T>(G+ 2×P×L'×H'× μ) / δ / C=Tmin; If the thermally responsive deformation component 4 gradually bends along the extension direction of the short side (e.g.) Figure 9 If ), then S 截 =A×T, Tmax=H_remainder>T>(G+ 2×P×L'×H'× μ) / δ / A=Tmin, where A is the side length dimension C that has not undergone deformation, i.e., Tmax=H_remainder>T>(G+ 2×P×L'×H'× μ) / δ / C=Tmin.

[0048] Therefore, in the direction perpendicular to the first side 11, the thickness T of the thermally responsive deformation element 4 before deformation satisfies the condition: T>(G+2×P×L'×H'×μ) / δ / C. Where: G is the gravity of the core assembly 2; P is the restraint pressure of the core assembly 2, which refers to the constant or adjustable mechanical pressure applied to the surface of the core assembly 2 by tooling (restraint plate, end plate, strap or box beam, etc.) during battery manufacturing and service in order to suppress the expansion of the core assembly 2 and keep its electrode interface tightly attached; L' is the length dimension of the core assembly 2 in the horizontal direction X, which is also the length dimension of the negative electrode sheet. There is restraint pressure on the two opposite surfaces of the core assembly 2 in the direction perpendicular to the horizontal direction X; H' is the height dimension of the core assembly 2 in the vertical direction Y, which is also the width of the negative electrode sheet. Dimension 1; μ is the coefficient of friction between the two opposing surfaces of the core assembly 2 in the direction perpendicular to the horizontal X and the inner wall of the housing 1. Considering the wetted interface between the aluminum shell and the smooth PP film under the immersion in carbonate electrolyte (such as EC / DMC / EMC system), the coefficient of friction μ can be any value in the range of 0.02 to 0.05, such as 0.02, 0.025, 0.03, 0.035, 0.04, 0.045, 0.05, which can be obtained through actual measurement; δ is the recovery stress of the thermally responsive deformation element 4 after deformation; C is the length of the side of the thermally responsive deformation element 4 that has not deformed when it is in the second state. If the thermally responsive deformation element 4 deforms along the extension direction of its long side and its short side does not deform, then the length of its short side is C; if the thermally responsive deformation element 4 deforms along the extension direction of its short side and its long side does not deform, then the length of its short side is C. In some embodiments, it is preferred that 0.1mm≤T≤0.6mm, for example, T=0.1mm, T=0.15mm, T=0.2mm, T=0.25mm, T=0.3mm, T=0.35mm, T=0.4mm, T=0.45mm, T=0.5mm, T=0.55mm, T=0.6mm.

[0049] In some embodiments, assuming the inner cavity height of the housing 1 is H (i.e., the distance between two opposing inner walls of the housing 1) and the height of the core assembly 2 is H' (which can be calculated from the width of the negative electrode sheet) in the direction perpendicular to the first side 11, then: d1 = (H - H') / 2, d1 < d2 < H - H'. Furthermore, in the direction perpendicular to the first side 11, the bulge height T' of the thermally responsive deformation element 4 after deformation satisfies the condition: T' = d2 < H - H'. Therefore, after the thermally responsive deformation element 4 deforms and supports the core assembly 2 to move upward, a gap can be maintained between the upper side of the core assembly 2 and the top inner side of the housing 1, avoiding local pressure accumulation and facilitating exhaust.

[0050] In some embodiments, the thickness T of the thermally responsive deformable element 4 before deformation satisfies the condition: T≤H 余 1mm≤H 余 ≤3mm, for example, H 余 =1mm, H 余 =1.25mm, H 余 =1.5mm, H 余 =1.75mm, H 余 =2mm, H 余 =2.25mm, H 余 =2.5mm, H 余 =2.75mm, H 余 =3mm. H 余 The diaphragm 22 in the core assembly 2 has a single-sided margin that exceeds the width of the negative electrode 21 in the direction perpendicular to the first side 11, i.e. (diaphragm width - negative electrode width) / 2.

[0051] As can be seen, the thermally responsive deformation element 4 provided in this application is a structural component designed based on the characteristics of the battery itself. It can reduce the adverse effects on the battery caused by excessive or insufficient thickness of the thermally responsive deformation element 4, which is beneficial to reducing the space occupied by the thermally responsive deformation element 4 within the single cell. This solves the problem of thermal runaway and cell explosion in single cells with explosion-proof valves at the bottom, without compromising battery performance or cell performance, and with minimal loss of energy density. When a single cell experiences thermal runaway, the thermally responsive deformation element 4 can automatically deform according to temperature changes, thereby supporting or even lifting the core assembly 2, forming a stable and effective air passage between the core assembly 2 and the casing 1, preventing the core assembly 2 from clogging the explosion-proof valve 3 and causing the battery to explode. Moreover, through the above design, it is compatible with existing battery manufacturing processes, with simple procedures and high yield.

[0052] In some embodiments, the thermally responsive deformation element 4 is a planar sheet-like structure parallel to a preset region before deformation. This planar sheet-like structure is... Figures 4 to 6 The solid plate shown, or the planar sheet structure, is a perforated plate with at least one vent hole or vent groove (not shown in the figure). The thermally responsive deformation element 4 can bend upwards or downwards after deformation. For example, the deformed thermally responsive deformation element 4 is an arc-shaped curved surface structure, with its arc-shaped opening facing a predetermined area on the inner side of the housing 1 (such as...). Figure 12 (as shown), or toward the core assembly 2 (such as Figure 11(As shown). However, it is not limited to this. In other embodiments, the thermally responsive deformable element 4 before deformation can also be made into any other sheet-like structure, and the thermally responsive deformable element 4 after deformation can also be designed into any other shape that can support the core assembly 2, such as a wave shape or a cylindrical shape with a cross-section close to a circle. Among them, when the thermally responsive deformable element 4 is deformed into the second state, it constitutes an exhaust structure. The groove 40 formed by its deformation serves as an exhaust channel, which not only supports the core assembly 2 but also prevents the core assembly 2 from being tightly fitted with the inner wall of the housing 1, thereby maintaining a gap distance between the core assembly 2 and the inner wall of the housing 1, ensuring that the gas inside the battery can be smoothly discharged.

[0053] In some embodiments, the material of the thermally responsive deformation component 4 is a shape memory alloy. It should be noted that a shape memory alloy is a metallic material with unique functional properties. Its core lies in its ability to undergo a reversible phase transformation between two different crystal structures (austenite and martensite) through temperature or stress changes, thereby achieving shape "memory" and recovery. In this design, this deformation is a one-way irreversible plastic deformation. The shape memory alloy can be any of nickel-titanium-based, copper-based, or iron-based shape memory alloys. Nickel-titanium-based shape memory alloys include variants such as Ni-Ti, Ni-Ti-Cu, Ni-Ti-Fe, and Ni-Ti-Nb; copper-based shape memory alloys include variants such as Cu-Zn-Al, Cu-Al-Ni, Cu-Zn-Sn, and Cu-Zn-Ga; and iron-based shape memory alloys include variants such as Fe-Mn-Si, Fe-Pt, Fe-Ni-Co-Ti, and Fe-Mn-Al-Ni. Among them, copper-based shape memory alloys have the characteristics of good elasticity, fast response and easy processing, while iron-based shape memory alloys have higher strength, hardness and stiffness. Both can play a good supporting role for the core component 2.

[0054] In some embodiments, the main material of the thermally responsive deformation element 4 is a shape memory alloy, and an encapsulating adhesive layer is provided on its surface. The material of the encapsulating adhesive layer can be any one of polyvinyl alcohol, silicone resin, or polyisobutylene adhesive, which can ensure the insulation between the thermally responsive deformation element 4 and the electrode. In specific implementation, the encapsulating adhesive layer can be formed on the surface of the shape memory alloy by impregnation and drying.

[0055] In some embodiments, the thermally responsive deformation element 4 includes a metal spring sheet layer and a heat-melted shaping layer. When the temperature of the thermally responsive deformation element 4 is lower than the trigger temperature, the heat-melted shaping layer is solid, and the metal spring sheet layer maintains a first state under the action of its own stiffness. When the temperature of the thermally responsive deformation element 4 is greater than or equal to the trigger temperature, the heat-melted shaping layer melts into a liquid state, and the metal spring sheet layer deforms into a second state under its own elasticity. Here, stiffness refers to the ability of an object or structure to resist deformation when subjected to force; elasticity refers to the property of an object to deform under the action of external force and to restore its original shape and size after the external force is removed. In specific implementations, the material of the heat-melted layer is a polymer that melts from a solid state to a liquid state (or a gaseous state or a gas-liquid mixture) when the temperature reaches the trigger temperature mentioned above. The thermally responsive deformation element 4 is a polymer-metal composite spring sheet, the polymer is the heat-melted shaping layer, and the metal spring sheet layer undergoes elastic deformation after heat melting.

[0056] In some embodiments, the explosion-proof valve 3 and the thermally responsive deformation element 4 are located below the electrode core assembly 2. Furthermore, in specific implementations, the thermally responsive deformation element 4 can be a single piece or multiple pieces, for example, such as... Figure 1 and Figure 2 As shown, a thermally responsive deformation element 4 is provided on the side of the explosion-proof valve 3 that is farther away from the second side 12 of the housing 1 in the vertical direction (the bottom of the second side 12 is perpendicularly connected to the short side of the first side 11); or, as shown... Figure 13 and Figure 14 As shown, at least one thermally responsive deformation element 4 is provided on each side of the explosion-proof valve 3.

[0057] In some embodiments, the core assembly 2 includes a core body composed of stacked electrode sheets and separators, and an insulating film wrapped around the core body, with a thermally responsive deformation element 4 composited on the insulating film. For example, the thermally responsive deformation element 4 is composited on the insulating film by adhesive bonding and / or heat-sealing. Specifically, the thermally responsive deformation element 4 is located on the side of the insulating film closer to a predetermined area, or on the side of the insulating film away from the predetermined area, or between two layers of insulating film. In some embodiments, the thermally responsive deformation element 4 is attached to a predetermined area on the inner wall of the housing 1 before deformation. When the temperature of the single cell reaches or approaches the trigger temperature of the thermally responsive deformation element 4, the insulating film connected to the thermally responsive deformation element 4 softens or even melts under the influence of high temperature, and the thermally responsive deformation element 4 deforms under the influence of high temperature, lifting the core assembly 2 to form an exhaust channel. However, it is not limited to this. In other embodiments, the thermally responsive deformation element 4 can be glued to a preset area on the inner wall of the housing 1 with glue or tape. When the temperature of the housing 1 reaches or approaches the trigger temperature of the thermally responsive deformation element 4, the glue or tape between the thermally responsive deformation element 4 and the housing 1 is affected by the high temperature, causing the adhesive function to fail (for example, the glue or tape melts due to the high temperature). The thermally responsive deformation element 4 is deformed due to the high temperature and lifts the core assembly 2 to form an exhaust channel.

[0058] In practical implementation, considering the frictional resistance between the core assembly 2 and the casing 1, at least Fsupport > G + Ffriction must be satisfied to allow the thermally responsive deformation element 4 to support the core assembly 2 and form a continuous and effective exhaust channel. Therefore, this application also provides a manufacturing method suitable for the single cell described above, through which a thermally responsive deformation element 4 meeting the requirements can be obtained. Specifically, the single cell manufacturing method includes the following steps: S1: The material of the thermally responsive deformation element 4 is selected based on the temperature at which a single cell experiences thermal runaway. The deformation trigger temperature (hereinafter referred to as the trigger temperature) of this material is within the temperature range at which the single cell experiences thermal runaway. That is, the trigger temperature of the material used to make the thermally responsive deformation element 4 is any value within the range of 105℃ to 250℃, such as 105℃, 110℃, 115℃, 120℃, 125℃, 130℃, 135℃, 140℃, 145℃, 150℃, 155℃, 160℃, 165℃, 170℃, 175℃. 180℃, 185℃, 190℃, 195℃, 200℃, 205℃, 210℃, 215℃, 220℃, 225℃, 230℃, 235℃, 240℃, 245℃, 250℃; furthermore, the triggering temperature is preferably any value within the range of 130℃ to 200℃, such as 130℃, 135℃, 140℃, 145℃, 150℃, 155℃, 160℃, 165℃, 170℃, 175℃, 180℃, 185℃, 190℃, 195℃, 200℃; S2: Determine the phase transformation recovery stress δ of the thermally responsive deformation component 4 based on the selected material; S3: Confirm the gravity G of the core component 2; in practice, first measure the mass m of the core component 2, and then convert it into gravity G. S4: Calculate the frictional resistance F_friction between the core assembly 2 and the inner wall of the housing 1. F_friction = F_pressure × μ = 2 × P × S × μ = 2 × P × L' × H' × μ; Where P is the restraint pressure (design value is generally taken as 0-10 kPa). Before and after thermal runaway valve opening, the gas causes the shell 1 to expand, and the frictional force is greatly reduced. Therefore, F_friction only needs to consider the part caused by the restraint pressure, and does not need to consider the part caused by the self-expansion force during the cell cycle. S is the contact area between the two large surfaces of the electrode core assembly 2 and the inner wall of the shell 1. Its maximum contact area S = L' × H', which can be found in [reference]. Figure 1 and Figure 2 ,or Figure 13 and Figure 14 Considering the wetted interface between the aluminum shell and the smooth PP film in a carbonate electrolyte (such as an EC / DMC / EMC system), the coefficient of friction μ can be any value within the range of 0.02 to 0.05, for example, 0.02, 0.025, 0.03, 0.035, 0.04, 0.045, 0.05, which can be obtained through actual measurement. Therefore, F_friction = F_pressure × μ = 2 × P × S × μ = 2 × P × L' × H' × μ.

[0059] S5: Calculate the supporting force Fsupport after the thermal response deformation component 4 is deformed. Fsupport = Ssection × δ, where Ssection is the cross-sectional area of ​​any deformation position of the thermal response deformation component 4. Generally, it refers to the cross-section of the deformation position where the thermal response deformation component 4 abuts against the core assembly 2 (or the inner wall of the housing 1) in the direction perpendicular to the bending direction. When the thermal response deformation component 4 is flat before deformation and arc-shaped after deformation, its maximum deformation position is generally the middle position of the arc-shaped plate. S6: Calculate the thickness T of the sheet-like thermally responsive deformable part 4 in the first state. The thickness T satisfies the condition Hexcess > T > (G + 2 × P × L' × H' × μ) / δ / N; where Fsupport > G + Ffriction, therefore Ssection × δ > G + 2 × P × L' × H' × μ, that is, Ssection > (G + 2 × P × L' × H' × μ) / δ; and since Ssection = C × T, therefore, C × T > (G + 2 × P × L' × H' × μ) / δ, that is, T > (G + 2 × P × L' × H' × μ) / δ / C; S7: Fabricate thermally responsive deformable part 4 with a curved structure in the second state, whose bulge height T' satisfies: T' < H-H'; S8: Fabricate a thermally responsive deformation part 4 with a sheet-like structure in the first state.

[0060] Furthermore, in some embodiments, the above-mentioned single-cell battery manufacturing method further includes step S9: immersing the thermally responsive deformation member 4, which has a sheet-like structure in the first state, into the adhesive solution, and then drying it to form an encapsulating adhesive layer on the surface of the thermally responsive deformation member 4.

[0061] The single-cell battery and its manufacturing method provided in this application are applicable to blade batteries. In this case, please refer to... Figures 10 to 12 In the core assembly 2, the bottom edge of the diaphragm 22 generally extends a certain distance beyond the bottom edge of the negative electrode 21. The thermally responsive deformation element 4 is located between the bottom edge of the diaphragm 22 and the inner bottom surface of the housing 1. Specifically, the thickness T of the thermally responsive deformation element 4 before deformation satisfies the condition: T≤H 余 1mm≤H 余 ≤3mm. H 余 The diaphragm 22 in the core assembly 2 has a single-sided margin that exceeds the width of the negative electrode 21 in the direction perpendicular to the first side 11, i.e. (diaphragm width - negative electrode width) / 2.

[0062] This application embodiment also provides a battery pack, in which a plurality of individual cells are arranged side by side, at least some of which are the individual cells described above that are provided with thermally responsive deformation elements 4.

[0063] This application also provides an electrical device, the battery system of which is provided with a battery pack as described above.

[0064] Furthermore, this application also provides several embodiments and comparative examples as described below.

[0065] Example 1 The design and manufacturing method of the thermally responsive deformation component 4 of a single-cell battery is as follows: The thermally responsive deformation component 4 is made of nickel-titanium based material, and its high-temperature deformation initiation temperature (i.e., the trigger temperature mentioned above) is 80℃. Based on the selected material, the alloy phase transformation recovery stress δ = 280 MPa was confirmed. The mass of the core assembly 2 was measured to be 1.5 kg. Given that the constraint pressure P of the core assembly 2 is 3000 Pa, and the dimensions L' and H' of the core assembly 2 are 345 mm and 99.8 mm respectively, and the coefficient of friction is 0.02, calculate the frictional resistance between the core assembly 2 and the housing 1: F 摩 = F 压 ×μ=2×P×S×μ=2×P×L’×H’×μ=4.13N; Before deformation, the length A of the thermally responsive deformable part 4 is 30mm and the width B is 15mm. After deformation, the short side of the thermally responsive deformable part 4 bends, while the long side does not bend. Therefore, S 截 =A×T, therefore the thickness of the thermally responsive deformation component 4 is calculated as T>(G+F) 摩 ) / δ / L1=T min =0.22mm, take the thickness T of thermally responsive deformation part 4 as 0.25mm, T<H 余 =1.8mm; The high-temperature thermal response deformation part 4 required for processing and manufacturing, namely the thermal response deformation part 4 in the second state in a bent state, has a bulge height T' of 4mm, which satisfies T'<H-H'; The low-temperature thermal response deformable part 4 required for processing and manufacturing, that is, the sheet-like thermal response deformable part 4 before deformation; The sheet-like thermally responsive deformable part 4 before deformation is immersed in the adhesive solution and dried to form an adhesive layer. The thermally responsive deformation element 4 is composited on the insulating film of the core assembly 2 and is attached to the bottom inner surface of the housing where the explosion-proof valve 3 is located; The thermally responsive deformation component 4 is bonded to the inner side of the insulating film using adhesive tape. The shape of the thermally responsive deformation component 4 after deformation is that the middle region bends upwards, as shown in the example. Figure 2 As shown; The battery was assembled according to the existing process and subjected to a thermal runaway test triggered by heating. The casing integrity rate was 5 / 5. The test parameters are detailed in Example 1 in the table.

[0066] Example 2 The design and manufacturing method of the thermally responsive deformation component 4 of a single-cell battery is as follows: The thermally responsive deformation component 4 is made of nickel-titanium based material, and its high-temperature deformation initiation temperature (i.e., the trigger temperature mentioned above) is 105℃. Based on the selected material, the alloy phase transformation recovery stress δ = 295 MPa was confirmed. The mass of the core assembly 2 was measured to be 1.5 kg. Given that the constraint pressure P of the core assembly 2 is 3000 Pa, and the dimensions L' and H' of the core assembly 2 are 345 mm and 99.8 mm respectively, and the coefficient of friction is 0.02, calculate the frictional resistance between the core assembly 2 and the housing 1: F 摩 = F 压 ×μ=2×P×S×μ=2×P×L’×H’×μ=4.13N; Before deformation, the length A of the thermally responsive deformable part 4 is 30mm and the width B is 15mm. After deformation, the short side of the thermally responsive deformable part 4 bends, while the long side does not bend. Therefore, S 截=A×T, therefore the thickness of the thermally responsive deformation component 4 is calculated as T>(G+F) 摩 ) / δ / L1=T min =0.21mm, take the thickness T of thermally responsive deformation part 4 as 0.25mm, T<H 余 =1.8mm; The high-temperature thermal response deformation part 4 required for processing and manufacturing, namely the thermal response deformation part 4 in the second state in a bent state, has a bulge height T' of 4mm, which satisfies T'<H-H'; The low-temperature thermal response deformable part 4 required for processing and manufacturing, that is, the sheet-like thermal response deformable part 4 before deformation; The sheet-like thermally responsive deformable part 4 before deformation is immersed in the adhesive solution and dried to form an adhesive layer. The thermally responsive deformation element 4 is composited on the insulating film of the core assembly 2 and is attached to the bottom inner surface of the housing where the explosion-proof valve 3 is located; The thermally responsive deformation component 4 is bonded to the inner side of the insulating film using adhesive tape. The shape of the thermally responsive deformation component 4 after deformation is that the middle region bends upwards, as shown in the example. Figure 2 As shown; The battery was assembled according to the existing process and subjected to a thermal runaway test triggered by heating. The casing integrity rate was 5 / 5. The test parameters are detailed in Example 2 in the table.

[0067] Example 3 The design and manufacturing method of the thermally responsive deformation component 4 of a single-cell battery is as follows: The thermally responsive deformation component 4 is made of nickel-titanium based material, and its high-temperature deformation initiation temperature (i.e., the trigger temperature mentioned above) is 150℃. Based on the selected material, the alloy phase transformation recovery stress δ = 320 MPa was confirmed. The mass of the core assembly 2 was measured to be 1.5 kg. Given that the constraint pressure P of the core assembly 2 is 3000 Pa, and the dimensions L' and H' of the core assembly 2 are 345 mm and 99.8 mm respectively, and the coefficient of friction is 0.02, calculate the frictional resistance between the core assembly 2 and the housing 1: F 摩 = F 压 ×μ=2×P×S×μ=2×P×L’×H’×μ=4.13N; Before deformation, the length A of the thermally responsive deformable part 4 is 30mm and the width B is 15mm. After deformation, the short side of the thermally responsive deformable part 4 bends, while the long side does not bend. Therefore, S 截 =A×T, therefore the thickness of the thermally responsive deformation component 4 is calculated as T>(G+F) 摩 ) / δ / A=T min =0.2mm, take the thickness T of the thermally responsive deformation component 4 as 0.2mm, T<H余 =1.8mm; The high-temperature thermal response deformation part 4 required for processing and manufacturing, namely the thermal response deformation part 4 in the second state in a bent state, has a bulge height T' of 4mm, which satisfies T'<H-H'; The low-temperature thermal response deformable part 4 required for processing and manufacturing, that is, the sheet-like thermal response deformable part 4 before deformation; The sheet-like thermally responsive deformable part 4 before deformation is immersed in the adhesive solution and dried to form an adhesive layer. The thermally responsive deformation element 4 is composited on the insulating film of the core assembly 2 and is attached to the bottom inner surface of the housing where the explosion-proof valve 3 is located; The thermally responsive deformation component 4 is bonded to the inner side of the insulating film using adhesive tape. The shape of the thermally responsive deformation component 4 after deformation is that the middle region bends upwards, as shown in the example. Figure 2 As shown; The battery was assembled according to the existing process and subjected to a thermal runaway test triggered by heating. The casing integrity rate was 5 / 5. The test parameters are detailed in Example 3 in the table.

[0068] Example 4 The design and manufacturing method of the thermally responsive deformation component 4 of a single-cell battery is as follows: The thermally responsive deformation component 4 is made of copper, and its high-temperature deformation initiation temperature (i.e., the trigger temperature mentioned above) is 130℃. Based on the selected material, the alloy phase transformation recovery stress δ = 195 MPa was confirmed. The mass of the core assembly 2 was measured to be 1.8 kg. Given that the constraint pressure P of the core assembly 2 is 4000 Pa, and the dimensions L' and H' of the core assembly 2 are 435 mm and 99.7 mm respectively, and the coefficient of friction is 0.02, the frictional resistance between the core assembly 2 and the housing 1 is calculated as follows: F_friction = F_pressure × μ = 2 × P × S × μ = 2 × P × L' × H' × μ = 6.94 N; Before deformation, the length A of the thermally responsive deformable part 4 is 40mm and the width B is 15mm. After deformation, the short side of the thermally responsive deformable part 4 is bent, while the long side is not bent. Therefore, S_section = A × T. Thus, the thickness T of the thermally responsive deformable part 4 is calculated to be greater than (G + F). 摩 ) / δ / A=T min =0.32mm, take the thickness T of thermally responsive deformation part 4 as 0.35mm, T<H 余 =2.0mm; The high-temperature thermal response deformation part 4 required for processing and manufacturing, namely the thermal response deformation part 4 that is in a bent state after deformation as described above, has a bulge height T' of 4mm, which satisfies T'<H-H'; The low-temperature thermal response deformable part 4 required for processing and manufacturing, that is, the thermal response deformable part 4 in the first state before deformation is sheet-like; The sheet-like thermally responsive deformable part 4 before deformation is immersed in the adhesive solution and dried to form an adhesive layer. The thermally responsive deformation element 4 is composited on the insulating film and is attached to the bottom inner surface of the housing where the explosion-proof valve 3 is located; The thermally responsive deformation component 4 is bonded to the inner side of the insulating film using adhesive tape. The shape of the thermally responsive deformation component 4 after deformation is that the middle region bends upwards, as shown in the example. Figure 2 As shown; The battery was assembled according to the existing process and subjected to a thermal runaway test triggered by heating. The casing integrity rate was 5 / 5. The test parameters are detailed in Example 4 in the table.

[0069] Example 5 The design and manufacturing method of the thermally responsive deformation component 4 of a single-cell battery is as follows: The thermally responsive deformation component 4 is made of copper, and its high-temperature deformation initiation temperature (i.e., the trigger temperature mentioned above) is 150℃. Based on the selected material, the alloy phase transformation recovery stress δ = 225 MPa was confirmed. The mass of the core assembly 2 was measured to be 1.5 kg. Given that the constraint pressure P of the core assembly 2 is 3000 Pa, and the dimensions L' and H' of the core assembly 2 are 345 mm and 99.7 mm respectively, and the coefficient of friction is 0.02, calculate the frictional resistance between the core assembly 2 and the housing 1: F 摩 = F 压 ×μ=2×P×S×μ=2×P×L’×H’×μ=4.13N; Before deformation, the length A of the thermally responsive deformable part 4 is 30mm and the width B is 15mm. After deformation, the short side of the thermally responsive deformable part 4 bends, while the long side does not bend. Therefore, S 截 =A×T, calculate the thickness T>(G+F) of the thermally responsive deformation component 4. 摩 ) / δ / A=T min =0.28mm, take the thickness T of thermally responsive deformation part 4 as 0.30mm, T<H 余 =1.8mm; The high-temperature thermal response deformation part 4 required for processing and manufacturing, namely the thermal response deformation part 4 that is in a bent state after deformation as described above, has a bulge height T' of 4mm, which satisfies T'<H-H'; The low-temperature thermal response deformable part 4 required for processing and manufacturing, that is, the thermal response deformable part 4 in the first state before deformation is sheet-like; The sheet-like thermally responsive deformable part 4 before deformation is immersed in the adhesive solution and dried to form an adhesive layer. The thermally responsive deformation element 4 is composited on the insulating film and is attached to the bottom inner surface of the housing where the explosion-proof valve 3 is located; The thermally responsive deformation component 4 is bonded to the inner side of the insulating film using adhesive tape. The shape of the thermally responsive deformation component 4 after deformation is that the middle region bends upwards, as shown in the example. Figure 2 As shown; The battery was assembled according to the existing process and subjected to a thermal runaway test triggered by heating. The casing integrity rate was 5 / 5. The test parameters are detailed in Example 5 of the table.

[0070] Example 6 The design and manufacturing method of the thermally responsive deformation component 4 of a single-cell battery is as follows: The thermally responsive deformation component 4 is made of copper, and its high-temperature deformation initiation temperature (i.e., the trigger temperature mentioned above) is 200℃. Based on the selected material, the alloy phase transformation recovery stress δ = 250 MPa was confirmed. The mass of the core assembly 2 was measured to be 1.5 kg. Given that the constraint pressure P of the core assembly 2 is 3000 Pa, and the dimensions L' and H' of the core assembly 2 are 345 mm and 99.6 mm respectively, and the coefficient of friction is 0.02, calculate the frictional resistance between the core assembly 2 and the housing 1: F 摩 = F 压 ×μ=2×P×S×μ=2×P×L’×H’×μ=4.12N; Before deformation, the length A of the thermally responsive deformable part 4 is 20mm and the width B is 15mm. After deformation, the short side of the thermally responsive deformable part 4 bends, while the long side does not bend. Therefore, S 截 =A×T, calculate the thickness T>(G+F) of the thermally responsive deformation component 4. 摩 ) / δ / A=T min =0.38mm, take the thickness T of thermally responsive deformation part 4 as 0.4mm, T < H 余 =1.8mm; The high-temperature thermal response deformation part 4 required for processing and manufacturing, namely the thermal response deformation part 4 that is in a bent state after deformation as described above, has a bulge height T' of 4mm, satisfying: T'<H-H'; The low-temperature thermal response deformable part 4 required for processing and manufacturing, that is, the thermal response deformable part 4 in the first state before deformation is sheet-like; The sheet-like thermally responsive deformable part 4 before deformation is immersed in the adhesive solution and dried to form an adhesive layer. The thermally responsive deformation element 4 is composited on the insulating film and is attached to the bottom inner surface of the housing where the explosion-proof valve 3 is located; The thermally responsive deformation component 4 is bonded to the inner side of the insulating film using adhesive tape. The shape of the thermally responsive deformation component 4 after deformation is that the middle region bends upwards, as shown in the example. Figure 2 As shown; The battery was assembled according to the existing process and subjected to a thermal runaway test triggered by heating. The casing integrity rate was 5 / 5. The test parameters are detailed in Example 6 of the table.

[0071] Example 7 The design and manufacturing method of the thermally responsive deformation component 4 of a single-cell battery is as follows: The thermally responsive deformation component 4 is made of iron, and its high-temperature deformation initiation temperature (i.e., the trigger temperature mentioned above) is 120℃. Based on the selected material, the alloy phase transformation recovery stress δ = 285 MPa was confirmed. The mass of the core assembly 2 was measured to be 1.5 kg. Given that the constraint pressure P of the core assembly 2 is 10000 Pa, the dimensions L' and H' of the core assembly 2 are 345 mm and 99.8 mm respectively, and the coefficient of friction is 0.02, calculate the frictional resistance between the core assembly 2 and the housing 1: F 摩 = F 压 ×μ=2×P×S×μ=2×P×L’×H’×μ=13.77N; Before deformation, the length A of the thermally responsive deformable part 4 is 30mm and the width B is 15mm. After deformation, the short side of the thermally responsive deformable part 4 bends, while the long side does not bend. Therefore, S 截 =A×T, calculate the thickness T>(G+F) of the thermally responsive deformation component 4. 摩 ) / δ / A=T min =0.33mm, take the thickness T of thermally responsive deformation part 4 as 0.35mm, T<H 余 =1.8mm; The high-temperature thermal response deformation part 4 required for processing and manufacturing, namely the thermal response deformation part 4 that is in a bent state after deformation as described above, has a bulge height T' of 4mm, satisfying: T'<H-H'; The low-temperature thermal response deformable part 4 required for processing and manufacturing, that is, the thermal response deformable part 4 in the first state before deformation is sheet-like; The sheet-like thermally responsive deformable part 4 before deformation is immersed in the adhesive solution and dried to form an adhesive layer. The thermally responsive deformation element 4 is composited on the insulating film and is attached to the bottom inner surface of the housing where the explosion-proof valve 3 is located; The thermally responsive deformation component 4 is bonded to the inner side of the insulating film using adhesive tape. The shape of the thermally responsive deformation component 4 after deformation is that the middle region bends upwards, as shown in the example. Figure 2 As shown; The battery was assembled according to the existing process and subjected to a thermal runaway test triggered by heating. The casing integrity rate was 5 / 5. The test parameters are detailed in Example 7 of the table.

[0072] Example 8 The design and manufacturing method of the thermally responsive deformation component 4 of a single-cell battery is as follows: The thermally responsive deformation component 4 is made of iron, and its high-temperature deformation initiation temperature (i.e., the trigger temperature mentioned above) is 250℃. Based on the selected material, the alloy phase transformation recovery stress δ = 440 MPa was confirmed. The mass of the core assembly 2 was measured to be 1.5 kg. Given that the constraint pressure P of the core assembly 2 is 10000 Pa, the dimensions L' and H' of the core assembly 2 are 345 mm and 99.8 mm respectively, and the coefficient of friction is 0.02, calculate the frictional resistance between the core assembly 2 and the housing 1: F 摩 = F 压 ×μ=2×P×S×μ=2×P×L’×H’×μ=13.77N; Before deformation, the length A of the thermally responsive deformable part 4 is 30mm and the width B is 15mm. After deformation, the short side of the thermally responsive deformable part 4 bends, while the long side does not bend. Therefore, S 截 =A×T, calculate the thickness T>(G+F) of the thermally responsive deformation component 4. 摩 ) / δ / A=T min =0.22mm, take the thickness T of thermally responsive deformation part 4 as 0.25mm, T<H 余 =1.8mm; The high-temperature thermal response deformation part 4 required for processing and manufacturing, namely the thermal response deformation part 4 that is in a bent state after deformation as described above, has a bulge height T' of 4mm, satisfying: T'<H-H'; The low-temperature thermal response deformable part 4 required for processing and manufacturing, that is, the thermal response deformable part 4 in the first state before deformation is sheet-like; The sheet-like thermally responsive deformable part 4 before deformation is immersed in the adhesive solution and dried to form an adhesive layer. The thermally responsive deformation element 4 is composited on the insulating film and is attached to the bottom inner surface of the housing where the explosion-proof valve 3 is located; The thermally responsive deformation component 4 is bonded to the inner side of the insulating film using adhesive tape. The shape of the thermally responsive deformation component 4 after deformation is that the middle region bends upwards, as shown in the example. Figure 2 As shown; The battery was assembled according to the existing process and subjected to a thermal runaway test triggered by heating. The casing integrity rate was 5 / 5. The test parameters are detailed in Example 8 in the table.

[0073] Example 9 The design and manufacturing method of the thermally responsive deformation element 4 of a single-cell battery is as follows: The thermally responsive deformation component 4 is made of iron, and its high-temperature deformation initiation temperature (i.e., the trigger temperature mentioned above) is 280℃. Based on the selected material, the alloy phase transformation recovery stress δ = 400 MPa was confirmed. The mass of the core assembly 2 was measured to be 1.5 kg. Given that the constraint pressure P of the core assembly 2 is 10000 Pa, the dimensions L' and H' of the core assembly 2 are 345 mm and 99.8 mm respectively, and the coefficient of friction is 0.02, calculate the frictional resistance between the core assembly 2 and the housing 1: F 摩 = F 压 ×μ=2×P×S×μ=2×P×L’×H’×μ=13.77N; Before deformation, the length A of the thermally responsive deformable part 4 is 30mm and the width B is 15mm. After deformation, the short side of the thermally responsive deformable part 4 bends, while the long side does not bend. Therefore, S 截 =A×T, calculate the thickness T>(G+F) of the thermally responsive deformation component 4. 摩 ) / δ / A=T min =0.24mm, take the thickness T of thermally responsive deformation part 4 as 0.25mm, T<H 余 =1.8mm; The high-temperature thermal response deformation part 4 required for processing and manufacturing, namely the thermal response deformation part 4 that is in a bent state after deformation as described above, has a bulge height T' of 4mm, satisfying: T'<H-H'; The low-temperature thermal response deformable part 4 required for processing and manufacturing, that is, the thermal response deformable part 4 in the first state before deformation is sheet-like; The sheet-like thermally responsive deformable part 4 before deformation is immersed in the adhesive solution and dried to form an adhesive layer. The thermally responsive deformation element 4 is composited on the insulating film and is attached to the bottom inner surface of the housing where the explosion-proof valve 3 is located; The thermally responsive deformation component 4 is bonded to the inner side of the insulating film using adhesive tape. The shape of the thermally responsive deformation component 4 after deformation is that the middle region bends upwards, as shown in the example. Figure 2 As shown; The battery was assembled according to the existing process and subjected to a thermal runaway test triggered by heating. The casing integrity rate was 5 / 5. The test parameters are detailed in Example 9 of the table.

[0074] Example 10 The design and manufacturing method of the thermally responsive deformation component 4 of a single-cell battery is as follows: The thermally responsive deformation component 4 is made of nickel-titanium based material, and its high-temperature deformation initiation temperature (i.e., the trigger temperature mentioned above) is 105℃. Based on the selected material, the alloy phase transformation recovery stress δ = 295 MPa was confirmed. The mass of the core assembly 2 was measured to be 1.5 kg. Given that the constraint pressure P of the core assembly 2 is 500 Pa, and the dimensions L' and H' of the core assembly 2 are 345 mm and 99.8 mm respectively, and the coefficient of friction is 0.02, calculate the frictional resistance between the core assembly 2 and the housing 1: F 摩 = F 压 ×μ=2×P×S×μ=2×P×L’×H’×μ=0.69N; Before deformation, the length A of the thermally responsive deformable part 4 is 30mm and the width B is 15mm. After deformation, the short side of the thermally responsive deformable part 4 bends, while the long side does not bend. Therefore, S 截 =A×T, calculate the thickness T>(G+F) of the thermally responsive deformation component 4. 摩 ) / δ / A=T min =0.17mm, take the thickness T of thermally responsive deformation part 4 as 0.2mm, T < H 余 =1.8mm; The high-temperature thermal response deformation part 4 required for processing and manufacturing, namely the thermal response deformation part 4 that is in a bent state after deformation as described above, has a bulge height T' of 4mm, satisfying: T'<H-H'; The low-temperature thermal response deformable part 4 required for processing and manufacturing, that is, the thermal response deformable part 4 in the first state before deformation is sheet-like; The sheet-like thermally responsive deformable part 4 before deformation is immersed in the adhesive solution and dried to form an adhesive layer. The thermally responsive deformation element 4 is composited on the insulating film and is attached to the bottom inner surface of the housing where the explosion-proof valve 3 is located; The thermally responsive deformation component 4 is bonded to the outside of the insulating film using adhesive tape. The shape of the thermally responsive deformation component 4 after deformation is that the middle region bends upwards, as shown in the example. Figure 2 As shown; The battery was assembled according to the existing process and subjected to a thermal runaway test triggered by heating. The casing integrity rate was 5 / 5. The test parameters are detailed in Example 10 in the table.

[0075] Example 11 The design and manufacturing method of the thermally responsive deformation component 4 of a single-cell battery is as follows: The thermally responsive deformation component 4 is made of nickel-titanium based material, and its high-temperature deformation initiation temperature (i.e., the trigger temperature mentioned above) is 105℃. Based on the selected material, the alloy phase transformation recovery stress δ = 295 MPa was confirmed. The mass of the core assembly 2 was measured to be 1.5 kg. Given that the constraint pressure P of the core assembly 2 is 3000 Pa, and the dimensions L' and H' of the core assembly 2 are 345 mm and 99.7 mm respectively, and the coefficient of friction is 0.05, calculate the frictional resistance between the core assembly 2 and the housing 1: F 摩 = F 压 ×μ=2×P×S×μ=2×P×L’×H’×μ=10.32N; Before deformation, the length A of the thermally responsive deformable part 4 is 30mm and the width B is 15mm. After deformation, the short side of the thermally responsive deformable part 4 bends, while the long side does not bend. Therefore, S 截 =A×T, calculate the thickness T>(G+F) of the thermally responsive deformation component 4. 摩 ) / δ / L1=T min =0.28mm, take the thickness T of thermally responsive deformation part 4 as 0.30mm, T<H 余 =1.8mm; The high-temperature thermal response deformation part 4 required for processing and manufacturing, namely the thermal response deformation part 4 that is in a bent state after deformation as described above, has a bulge height T' of 4mm, satisfying: T' < H-H'; The low-temperature thermal response deformable part 4 required for processing and manufacturing, that is, the thermal response deformable part 4 in the first state before deformation is sheet-like; The sheet-like thermally responsive deformable part 4 before deformation is immersed in the adhesive solution and dried to form an adhesive layer. The thermally responsive deformation element 4 is composited on the insulating film and is attached to the bottom inner surface of the housing where the explosion-proof valve 3 is located; The thermally responsive deformation component 4 is bonded to the inner side of the insulating film using adhesive tape. The shape of the thermally responsive deformation component 4 after deformation is that the middle region bends upwards, as shown in the example. Figure 2 As shown; The battery was assembled according to the existing process and subjected to a thermal runaway test triggered by heating. The casing integrity rate was 5 / 5. The test parameters are detailed in Example 11 in the table.

[0076] Comparative Example 1 Batteries without shape memory alloys. A thermal runaway test was conducted, with a 4 / 5 probability of casing explosion. Test parameters are detailed in Comparative Example 1 in the table.

[0077] Comparative Example 2 A battery was made by replacing the thermally responsive deformation component 4 with a 3mm aluminum block. A thermal runaway test was conducted, and the casing integrity rate was 5 / 5. Test parameters are detailed in Comparative Example 2 in the table. However, the aluminum block is relatively thick and heavy, which negatively impacts the battery's energy density.

[0078] In summary, when a thermally responsive deformation element 4, designed based on the battery's own characteristics, is provided below the core assembly 2 in the single-cell battery provided in this application embodiment, not only can the space occupied by the thermally responsive deformation element 4 within the battery be greatly reduced, but it also has virtually no impact on the volumetric energy density and battery performance. When the battery is heated or experiences thermal runaway, and the temperature reaches the trigger temperature of the thermally responsive deformation element 4, causing the thermally responsive deformation element 4 to deform, the deformed thermally responsive deformation element 4 can quickly lift the core assembly 2, thereby expanding the gap between the core assembly 2 and the casing 1 at and near the location of the explosion-proof valve 3 and forming an exhaust channel. This prevents the core assembly 2 from blocking the explosion-proof valve 3, ensuring smooth exhaust and pressure relief, and ultimately achieving the purpose of suppressing the battery from thermal runaway and casing explosion.

[0079] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed.

[0080] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0081] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A single-cell battery, comprising a housing (1) and an electrode assembly (2) located within the housing (1), wherein an explosion-proof valve (3) is provided on a first side (11) of the housing (1), the first side (11) being the bottom surface of the housing (1), characterized in that, It also includes a thermally responsive deformation element (4), which is located between a preset area of ​​the inner wall of the first side surface (11) and the bottom surface of the core assembly (2); In a direction perpendicular to the first side surface (11), the thermally responsive deformable element (4) contacts the diaphragm (22) in the core assembly (2) beyond the negative electrode sheet (21) by a margin, and the thickness T of the thermally responsive deformable element (4) before deformation satisfies the condition: T≤H 余 1mm≤H 余 ≤3mm, H 余 The diaphragm (22) in the core assembly (2) has a width that exceeds the width of the negative electrode (21) on one side in a direction perpendicular to the first side (11); and the thickness T of the thermally responsive deformation element (4) before deformation is any value in the range of 0.1 mm to 0.6 mm. When the temperature of the thermally responsive deformation element (4) is less than the trigger temperature: the thermally responsive deformation element (4) maintains a first state; in the direction perpendicular to the first side surface (11), the gap distance between the preset area and the pole core assembly (2) is a first gap distance d1; the trigger temperature is any value within the range of 130°C to 200°C; When the temperature of the thermally responsive deformation element (4) is greater than or equal to the trigger temperature: the thermally responsive deformation element (4) deforms into a second state and supports the core assembly (2) to move away from the preset area; in the direction perpendicular to the first side surface (11), the gap distance between the preset area and the core assembly (2) is the second gap distance d2, d1 < d2 < H-H'; in the direction perpendicular to the first side surface (11), the inner cavity height of the housing (1) is H, and the height of the core assembly (2) is H'.

2. The single-cell battery according to claim 1, characterized in that, The thermally responsive deformation element (4) is located between the bottom of the core assembly (2) and the first side surface (11); In the direction perpendicular to the first side (11), the thickness T of the thermally responsive deformation member (4) before deformation satisfies the condition: T>(G+2×P×L'×H'×μ) / δ / C; G is the gravity of the core assembly (2); P is the restraint pressure of the core assembly (2); L' is the length dimension of the core assembly (2) in the horizontal direction (X), and there is a restraint pressure on both sides of the core assembly (2) in the horizontal direction (X); H' is the height dimension of the pole core assembly (2) in the vertical direction (Y); μ is the coefficient of friction between the two side surfaces of the core assembly (2) in the horizontal direction (X) and the inner wall of the housing (1); δ is the recovery stress of the thermally responsive deformation component (4) after deformation; C is the side length dimension of the thermally responsive deformation component (4) when it is in the second state and has not deformed.

3. The single-cell battery according to claim 1, characterized in that, Before deformation, the thermally responsive deformation component (4) is a planar sheet structure parallel to the preset area; the planar sheet structure is a solid plate, or the planar sheet structure is a hollow plate with at least one ventilation hole or ventilation groove. The thermally responsive deformation component (4) is deformed into an arc-shaped curved surface structure, with its arc-shaped opening facing the preset area or the pole core assembly (2).

4. The single-cell battery according to claim 1, characterized in that, The material of the thermally responsive deformation component (4) is a shape memory alloy; Alternatively, the thermally responsive deformation element (4) may comprise a metal spring layer and a hot-melt shaping layer: When the temperature of the thermally responsive deformation element (4) is lower than the trigger temperature, the hot melt shaping layer is solid, and under the action of the self-stiffness of the hot melt shaping layer, the metal spring sheet layer maintains the first state. When the temperature of the thermally responsive deformation element (4) is greater than or equal to the trigger temperature, the hot-melt shaping layer melts into a liquid state, and the metal spring sheet layer deforms into the second state under its own elastic action.

5. The single-cell battery according to claim 1, characterized in that, The surface of the thermally responsive deformation component (4) is provided with an encapsulating adhesive layer.

6. The single-cell battery according to claim 1, characterized in that, The explosion-proof valve (3) is provided with the thermally responsive deformation element (4) on the side of the housing (1) that is farther away from the second side (12) in the vertical direction. Alternatively, at least one thermally responsive deformation element (4) is provided on each side of the explosion-proof valve (3). And / or, the core assembly (2) includes a core body composed of stacked electrode sheets and diaphragms, and an insulating film wrapped around the core body, wherein the thermally responsive deformation element (4) is composited on the insulating film; And / or, the thermally responsive deformation element (4) is attached to the preset area before deformation.

7. The single-cell battery according to claim 6, characterized in that, The thermally responsive deformation element (4) is bonded to the insulating film by means of adhesive bonding and / or hot-melt encapsulation.

8. The single-cell battery according to claim 1, characterized in that, The individual battery includes blade batteries.

9. A method for manufacturing a single-cell battery according to any one of claims 1 to 8, characterized in that, The manufacturing method includes: S1: Select the material of the thermally responsive deformation element (4) according to the temperature when the single cell experiences thermal runaway, and the trigger temperature of the material is within the temperature range when the single cell experiences thermal runaway; S2: Determine the phase transformation recovery stress δ of the thermally responsive deformation component (4) based on the selected material; S3: Confirm the gravity G of the core assembly (2); S4: Calculate the frictional resistance F between the core assembly (2) and the inner wall of the housing (1). 摩 F 摩 = F 压 ×μ=2×P×S×μ=2×P×L'×H'×μ; F 压 The pressure exerted by the core assembly (2) on the housing (1); μ is the coefficient of friction between the two side surfaces of the core assembly (2) in the horizontal direction (X) and the inner wall of the housing (1); P is the restraint pressure of the core assembly (2); S is the contact area of ​​a single inner side surface of the pole core assembly (2) and the housing (1) in the horizontal direction (X); L' is the length dimension of the core assembly (2) in the horizontal direction (X), and there is a restraint pressure on both sides of the core assembly (2) in the horizontal direction (X); H' is the height dimension of the pole core assembly (2) in the vertical direction (Y); S5: Calculate the supporting force F after the thermally responsive deformation component (4) has deformed. 支 F 支 =S 截 ×δ,S 截 The cross-sectional area of ​​the thermally responsive deformable element (4) at any deformation location within a section perpendicular to the deformation direction; S6: Calculate the thickness T of the thermally responsive deformation element (4) in the first state with a sheet-like structure, wherein the thickness T satisfies the condition T>(G+2×P×L'×H'×μ) / δ / C; G is the gravity of the core assembly (2); δ is the recovery stress of the thermally responsive deformation component (4) after deformation; C is the side length dimension of the thermally responsive deformation component (4) when it is in the second state and has not deformed; S7: The thermally responsive deformable part (4) with a curved structure in the second state is processed and manufactured, and its bulge height T' satisfies: T' < H-H'; In a direction perpendicular to the first side (11), the inner cavity height of the housing (1) is H, and the height of the pole core assembly (2) is H'; S8: Process and manufacture the thermally responsive deformable part (4) that has a sheet-like structure in the first state.

10. The manufacturing method according to claim 9, characterized in that, Also includes: S9: Immerse the thermally responsive deformable part (4) in the first state, which has a sheet-like structure, into the adhesive liquid, and after drying, form an encapsulating adhesive layer on the surface of the thermally responsive deformable part (4).

11. A battery pack comprising a plurality of individual batteries arranged side by side, characterized in that, At least a portion of the said single cell is the single cell according to any one of claims 1 to 8.

12. An electrical device comprising a battery system, characterized in that, The battery system is provided with the battery pack as described in claim 11.

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