Battery pole piece, battery and electric device

Abstract

The application provides a battery pole piece, a battery and a power utilization device, and belongs to the technical field of batteries. The battery pole piece comprises at least one thermal trigger area; under a misuse condition of the battery, the thermal trigger area triggers thermal runaway earlier than other areas of the battery pole piece. The application converts unpredictable thermal runaway events into predictable directional pressure relief processes through a battery pole piece design with an active guidance function, thereby fundamentally improving the safety of the battery system and the effectiveness of the protection design.

Description

Technical Field

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

[0002] With the rapid development of new energy vehicles and large-scale energy storage industries, batteries are evolving towards higher energy density and larger single-cell capacity. The increasing size of battery cells directly leads to a sharp increase in the total chemical energy stored inside them. This means that once thermal runaway occurs, the intensity and destructive power of the released energy increase exponentially, manifesting as higher temperatures, more violent reactions, and more intense ejection.

[0003] However, due to differences in manufacturing processes and usage environments, the location of thermal runaway in batteries is unpredictable. When the actual location of thermal runaway deviates significantly from the design assumptions, the effectiveness of protective measures will be greatly reduced. This may lead to serious consequences such as untimely pressure relief, high-temperature ejected material impacting in unexpected directions, and heat not being effectively isolated, resulting in chain thermal propagation, which greatly increases the safety risks of the battery system. Summary of the Invention

[0004] This application provides a battery electrode, a battery, and an electrical device. Through a battery electrode design with active guidance function, unpredictable thermal runaway events are transformed into predictable directional pressure relief processes, thereby fundamentally improving the safety of the battery system and the effectiveness of its protection design.

[0005] To achieve the above objectives, the first aspect of this application provides a battery electrode, comprising: at least one thermal triggering region; Under battery abuse conditions, the thermal trigger zone triggers thermal runaway before other areas of the battery electrode.

[0006] This application provides a battery electrode with active safety guidance. By setting at least one thermal trigger zone on the battery electrode, whose thermal runaway trigger threshold is lower than that of other areas of the electrode, when the battery electrode encounters battery abuse conditions such as overcharging, overheating, or short circuits, the destructive thermal runaway reaction will be forcibly guided to occur preferentially in this thermal trigger zone. This transforms the originally random and unpredictable failure mode into a unified and predictable failure mode. This provides deterministic input conditions for safety design at the cell and / or battery level (such as directional pressure relief channels, locally reinforced casings, targeted heat insulation and heat dissipation designs, etc.), making the design goals of overall safety measures clearer, fundamentally improving protection efficiency and reliability, effectively avoiding pressure relief failures and uncontrolled propagation of thermal runaway caused by uncertain thermal runaway locations, and enhancing battery safety.

[0007] In some embodiments, the thermal triggering region is provided with a thermal response impedance change layer and / or a catalytically active material layer.

[0008] In some implementations, the resistivity of the thermally responsive impedance-changing layer increases by at least 100% under battery abuse conditions.

[0009] In some embodiments, the thermally responsive impedance variation layer comprises a thermally conductive filler and a thermally responsive polymer matrix.

[0010] In some embodiments, the thermally conductive filler includes at least one of conductive carbon black, graphene, and carbon nanotubes.

[0011] In some embodiments, the thermally responsive polymer matrix includes at least one of polyacrylic acid, polyvinylidene fluoride, polyvinylidene fluoride copolymer, polystyrene, styrene-butadiene rubber, and thermoplastic polyurethane elastomer.

[0012] In some embodiments, the amount of thermally conductive filler added is 3~95 wt.%.

[0013] In some embodiments, the content of catalytic metal elements in the catalytic active material layer is higher than the content of catalytic metal elements in other regions of the battery electrode.

[0014] In some embodiments, the catalytic metal element includes at least one of iron, titanium, copper, and manganese.

[0015] In some embodiments, the content of catalytic metal elements in the catalytic active material layer is 200 to 10,000 PPM higher than the content of catalytic metal elements in other regions of the battery electrode.

[0016] In some embodiments, the thermally triggered region occupies 10-50% of the total area of ​​the battery electrode.

[0017] In some embodiments, the thermal triggering zone is located on the side of the battery electrode near the explosion-proof valve.

[0018] In some embodiments, the thermal triggering zone is located in a non-central region of the battery electrode.

[0019] In some embodiments, the battery electrode includes a positive electrode.

[0020] A second aspect of this application provides a battery including the battery electrodes as described above.

[0021] A third aspect of this application provides an electrical device, including at least one of the battery electrode of the first aspect of this application and the battery of the second aspect of this application. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the battery electrode as described in application 1. Figure 1 ; Figure 2 This is a schematic diagram of the battery electrode as described in application 1. Figure 2 ; Figure 3 This is a schematic diagram of the battery electrode as described in application 1. Figure 3 ; Figure 4 This is a schematic diagram of the battery electrode as described in application 1. Figure 4 ; Figure 5 This is a schematic diagram of a battery according to one embodiment of this application; Figure 6 This is a graph showing the temperature rise and voltage change of the battery electrode under overcharge conditions in Embodiment 1 of this application.

[0023] Explanation of reference numerals in the attached figures 100. Battery electrode; 101. Thermal trigger zone; 102. Other areas (non-trigger zone); 103. Central area; 104. Non-central area; 201. Explosion-proof valve. Detailed Implementation

[0024] The following detailed description, with appropriate reference to the accompanying drawings, specifically discloses embodiments of the battery electrode, battery, and power-consuming device of this application. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of practically identical structures may be omitted. This is to avoid unnecessarily lengthy descriptions and to facilitate understanding by those skilled in the art. Furthermore, the accompanying drawings and the following description are provided for the purpose of enabling those skilled in the art to fully understand this application and are not intended to limit the subject matter of the claims.

[0025] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0026] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0027] Unless otherwise specified, all steps of this application may be performed sequentially or randomly, preferably sequentially. For example, if the method includes steps (a) and (b), it means that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, if the method may also include step (c), it means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0028] In conventional technologies, due to differences in the microscopic uniformity of electrode slurry coating, insufficient localized electrolyte wetting, process fluctuations during production, and internal state differentiation caused by aging and uneven temperature distribution during long-term battery use, the chemical and physical states of different regions within the battery cell inherently differ. This leads to thermal runaway triggers, such as internal short circuits and hotspots with the most intense side reactions, potentially appearing randomly at any location within the cell, including the top, middle, bottom, side, or corner. In other words, the location of thermal runaway within the battery exhibits a high degree of randomness and uncertainty. This randomness in failure location poses a fundamental challenge to traditional safety protection systems based on fixed preset locations. Whether it's the layout of the casing's explosion-proof valve, the laying of internal insulation materials, or the planning of thermal management paths, all require optimized design for specific failure scenarios and pressure release paths. When the actual location of thermal runaway deviates significantly from the design assumptions, the effectiveness of protective measures will be greatly reduced, potentially leading to serious consequences such as untimely pressure relief, unexpected impact of high-temperature ejected materials, and chain thermal propagation due to ineffective heat isolation, significantly increasing the safety risks of the battery system.

[0029] Based on this, this application provides a battery electrode with active safety guidance function. By setting at least one thermal trigger zone on the battery electrode, whose thermal runaway trigger threshold is lower than that of other areas of the electrode, when the battery electrode encounters battery abuse conditions such as overcharging, overheating, or short circuits, the destructive thermal runaway reaction will be forcibly guided to occur preferentially in this thermal trigger zone, thereby transforming the originally random and unpredictable failure mode into a unified and predictable failure mode. This provides deterministic input conditions for safety design at the cell and / or battery level (such as directional pressure relief channels, locally reinforced casings, targeted heat insulation and heat dissipation designs, etc.), making the design goals of overall safety measures clearer, fundamentally improving protection efficiency and reliability, effectively avoiding pressure relief failures and uncontrolled propagation of thermal runaway caused by uncertain thermal runaway locations, and enhancing battery safety.

[0030] The first aspect of this application provides an electrode sheet including at least one thermal triggering region; under battery abuse conditions, the thermal triggering region triggers thermal runaway before other regions of the battery electrode sheet.

[0031] Battery abuse conditions refer to a series of extreme test conditions or unexpected operating conditions that can lead to irreversible performance degradation or safety failure of the battery. These conditions are sufficient to trigger a self-accelerating exothermic reaction chain inside the battery, i.e., thermal runaway.

[0032] In some embodiments of this application, battery abuse conditions include at least one of the following: electrical abuse, thermal abuse, and mechanical abuse.

[0033] In some embodiments of this application, electrical abuse, i.e., electrical operation that exceeds the normal operating voltage or current window of the battery, includes at least one of overcharging, over-discharging, and external short circuit.

[0034] In some embodiments of this application, thermal abuse refers to an abnormal increase in the ambient temperature or local temperature of the battery, including external heating and / or local overheating.

[0035] In some embodiments of this application, mechanical abuse refers to external forces that cause physical deformation or damage to the battery, including at least one of: squeezing, puncture, drop, vibration, and impact.

[0036] In some embodiments of this application, the temperature rise rate of the thermal trigger zone is greater than or equal to 0.02℃ / min, while the temperature rise rate of other areas of the battery electrode (i.e., non-trigger zone) is less than 0.02℃ / min.

[0037] For example, refer to Figure 1 The battery electrode 100 includes an adjacent thermally triggered region 101 and a non-triggered region 102.

[0038] For example, refer to Figure 2 The battery electrode 100 includes a non-trigger area 102 and a thermal trigger area 101 disposed on both sides of the non-trigger area 102.

[0039] In this embodiment, by setting at least one thermal trigger zone on the battery electrode, whose thermal runaway trigger threshold is lower than that of other areas of the electrode, when the battery electrode encounters battery abuse conditions such as overcharging, overheating, or short circuits, the destructive thermal runaway reaction will be forcibly guided to occur preferentially in this thermal trigger zone. This transforms the originally random and unpredictable failure mode into a unified and predictable failure mode. This provides deterministic input conditions for the safety design at the cell and / or battery level (such as directional pressure relief channels, locally reinforced casings, targeted heat insulation and heat dissipation designs, etc.), making the design goals of the overall safety measures clearer, fundamentally improving protection efficiency and reliability, effectively avoiding pressure relief failures and uncontrolled propagation of thermal runaway caused by uncertain thermal runaway locations, and enhancing battery safety.

[0040] In some embodiments, the thermal triggering region is provided with a thermal response impedance change layer and / or a catalytically active material layer.

[0041] The thermal response impedance change layer refers to a functional coating formed on a predetermined local area (i.e., thermal triggering area) of a battery electrode (such as a positive electrode or a negative electrode) by means of coating, printing or lamination. The macroscopic resistivity of this layer is highly sensitive to changes in external temperature or its own temperature, and exhibits a significant positive temperature coefficient effect (i.e., the resistivity increases significantly with its own temperature).

[0042] The catalytic active material layer refers to a functionalized region formed on the thermal triggering region of a battery electrode (such as the positive electrode) by designing the catalytic active material in this layer.

[0043] In some embodiments of this application, the battery electrode may be provided with one or more thermal triggering regions; if the battery electrode is provided with multiple thermal triggering regions, the thermal triggering regions may be at least partially adjacent or not adjacent to each other; each thermal triggering region may be provided with at least partially the same or different functional layers (i.e., thermal response impedance change layer and / or catalytic active material layer).

[0044] In some embodiments of this application, the coating thickness and areal density are basically consistent between the thermally triggered region and the non-thermally triggered region.

[0045] In some embodiments, the thermally responsive impedance variation layer includes a thermally conductive filler and a thermally responsive polymer matrix.

[0046] In some embodiments of this application, the thermally responsive impedance change layer is composed of a continuous phase (i.e., a thermally responsive polymer matrix) and a dispersed phase (i.e., a thermally conductive filler). Within the normal operating temperature range of the battery, the thermally responsive polymer matrix remains stable and dense, and a complete, low-resistivity conductive network is formed between the thermally conductive fillers, resulting in a low resistivity for this functional layer. When the battery is subjected to abuse conditions such as overcharging, external heating, or internal short circuits, causing the temperature in this local area to rise to a preset trigger threshold (e.g., above 80°C), the thermally responsive polymer matrix undergoes severe swelling or deformation. The volume expansion causes the originally tightly contacted thermally conductive filler particles to be forcibly pushed apart, and the conductive network is physically damaged or elongated. This results in a rapid increase in the overall volume resistivity of the layer within a narrow temperature range. According to Joule's law, under the influence of the subsequent abuse current flowing through this area, since the resistance has become extremely high, electrical energy will be converted into Joule heat with exceptionally high efficiency. This causes the temperature rise rate and final peak temperature of the thermally triggered area where the thermally responsive impedance change layer is located to far exceed any other area inside the battery in a very short time. This controlled, intense localized overheating ensures that the chain reaction of thermal runaway is forcibly guided to the thermal trigger zone, thereby enabling spatial localization and proactive management of thermal runaway events.

[0047] In some implementations, the resistivity of the thermally responsive impedance-changing layer increases by at least 100% under battery abuse conditions.

[0048] In some embodiments of this application, under battery abuse conditions, the resistivity of the thermally responsive impedance change layer increases to at least twice its initial value (i.e., the resistivity at normal operating temperature).

[0049] In some embodiments of this application, under battery abuse conditions, the resistivity of the thermally responsive impedance change layer experiences a jump of at least one order of magnitude.

[0050] In some embodiments, the thermally conductive filler includes at least one of conductive carbon black, graphene, and carbon nanotubes.

[0051] In some embodiments of this application, at least one of conductive carbon black, graphene, and carbon nanotubes has excellent chemical stability and electrochemical inertness, does not undergo side reactions within the battery operating voltage window, and can efficiently construct a stable three-dimensional percolating conductive network.

[0052] In some embodiments, the thermally responsive polymer matrix includes at least one of polyacrylic acid, polyvinylidene fluoride, polyvinylidene fluoride copolymer, polystyrene, styrene-butadiene rubber, and thermoplastic polyurethane elastomer.

[0053] In some embodiments of this application, at least one of polyacrylic acid, polyvinylidene fluoride, polyvinylidene fluoride copolymer, polystyrene, styrene-butadiene rubber, and thermoplastic polyurethane elastomer can provide diverse and controllable thermal response behaviors ranging from strong swelling to significant phase change, and is highly compatible with conventional battery systems.

[0054] In some embodiments, the amount of thermally conductive filler added is 3 to 95 wt.% (mass percentage / mass ratio).

[0055] In some embodiments of this application, the mass percentage of thermally conductive filler in the total mass of the thermally responsive impedance change layer is 3%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, etc. If the amount of thermally conductive filler added is less than 3 wt.%, the coating is difficult to conduct electricity under normal conditions, and therefore cannot generate Joule heating through subsequent resistance increase, resulting in functional failure. If the amount of thermally conductive filler added is greater than 95 wt.%, the polymer matrix content is too low, the coating will be too rigid, and it will lose its elasticity and deformability; even if the temperature rises, the polymer will not be able to swell sufficiently to effectively break the rigid conductive network formed by the tightly packed filler, resulting in sluggish resistance temperature response or even failure. Therefore, embodiments of this application limit the amount of thermally conductive filler added to 3~95 wt.%.

[0056] In some embodiments of this application, within the normal temperature range (e.g., 20~60°C), the thermal response impedance change layer in the thermally triggered region and the electrode active material layer in the non-thermally triggered region have similar electronic conductivity. For example, the resistance deviation between the thermal response impedance change layer and the electrode active material layer is ≤15%. This ensures that the functional layer does not introduce significant additional impedance or electrochemical polarization during most of the battery's operation time, thereby avoiding its negative impact on the battery's core performance such as energy density, rate performance, and cycle life.

[0057] In some embodiments, the content of catalytic metal elements in the catalytic active material layer is higher than the content of catalytic metal elements in other regions of the battery electrode.

[0058] In some embodiments of this application, under abusive conditions such as overcharging, external thermal shock, and internal short circuits, a series of chain-like exothermic side reactions will occur inside the battery, including: oxidative decomposition of the electrolyte under high voltage, destabilization of the crystal structure of the positive electrode active material and release of oxygen, and a violent oxidation reaction between the released active oxygen and the electrolyte. At this time, the high concentration of catalytic metal elements in the catalytic active material layer can serve as highly efficient heterogeneous catalytic active centers, significantly accelerating the kinetic rate of the aforementioned exothermic side reactions by providing alternating redox pairs, reducing the activation energy of the reaction, or changing the reaction pathway. Furthermore, because the catalytic effect is precisely confined within the thermal trigger zone, the exothermic power / rate per unit time in this region increases sharply under battery abuse conditions, resulting in a local temperature rise rate and a final peak temperature that far exceed those of other areas of the battery. This concentrated and intense exothermic effect ensures that the chain reaction of thermal runaway is forcibly guided to this thermal trigger zone for preferential triggering and development, thereby transforming the originally random and uncontrollable thermal runaway failure mode into a spatially fixed, predictable, and targeted safety protection mechanism.

[0059] In some embodiments of this application, other areas of the battery electrode refer to areas other than the thermal triggering area, i.e., non-triggering areas, and the thermal triggering area does not overlap with other areas of the battery electrode.

[0060] In some embodiments of this application, catalytic metal elements can be doped into the catalytically active material layer in ionic form, or they can exist in the catalytically active material layer in the form of oxides, salts, or other compounds.

[0061] In some embodiments, the catalytic metal element includes at least one of iron, titanium, copper, and manganese.

[0062] In some embodiments of this application, at least one of iron (Fe), titanium (Ti), copper (Cu) and manganese (Mn) possesses characteristics such as high catalytic activity, cost controllability, and compatibility with cathode material systems under battery abuse conditions, and is therefore suitable as a catalytic metal element.

[0063] Iron (Fe) has multiple valence states (Fe... 2+ / Fe 3+ It can efficiently catalyze the decomposition of peroxides (such as electrolyte decomposition products) to generate highly active free radicals, which drastically accelerate the chain oxidation reaction.

[0064] Titanium (Ti) is usually classified as Ti 4+It exists in a form that has a strong oxygen affinity and can effectively reduce the activation energy for the evolution of lattice oxygen on the surface of the cathode material, thereby catalyzing the oxygen release reaction of the cathode under overcharge or high temperature. This is one of the most critical high-exothermic steps in the early stage of thermal runaway.

[0065] Copper (Cu) is also a highly efficient redox catalyst, especially under high pressure, it can significantly accelerate the decomposition reactions of carbonate electrolytes such as dehydrogenation and polymerization, and may migrate to the positive electrode surface after local corrosion of the current collector (usually aluminum).

[0066] Manganese (Mn) is a constituent element of many cathode materials (such as LiMn2O4 and NCM), while high-valence manganese ions (such as Mn) are also important components. 3+ (Proliferating) can catalyze the decomposition of electrolyte and undergo a change in its valence state under conditions of abuse, causing severe localized exothermic reactions.

[0067] In some embodiments, the content of catalytic metal elements in the catalytic active material layer is 200 to 10,000 PPM higher than the content of catalytic metal elements in other regions of the battery electrode.

[0068] In some embodiments of this application, the content of catalytic metal elements in the catalytic active material layer is 200 PPM, 500 PPM, 1000 PPM, 1500 PPM, 2000 PPM, 2500 PPM, 3000 PPM, 3500 PPM, 4000 PPM, 4500 PPM, 5000 PPM, 5500 PPM, 6000 PPM, 6500 PPM, 7000 PPM, 7500 PPM, 8000 PPM, 8500 PPM, 9000 PPM, 9500 PPM, 10000 PPM, etc., higher than the content of catalytic metal elements in other regions of the battery electrode. Among them, 200 PPM is the minimum effective threshold to ensure the catalytic effect; when abuse conditions occur, the number of catalytic centers at this concentration is sufficient to form a significant catalytic effect locally, making the exothermic rate exceed that of other regions; while setting the upper limit to 10,000 PPM can avoid the negative effects that excessive doping may cause (such as affecting lithium-ion insertion / extraction kinetics and cycle performance, or prematurely initiating side reactions in normal cycling, etc.), while ensuring the stability of the battery's basic electrochemical performance.

[0069] In some embodiments of this application, the functional layer (i.e., the thermal response impedance change layer and / or the catalytic active material layer) disposed on the thermal trigger region can be disposed on the electrode active material layer as an additional functional coating, or it can be integrated into the electrode active material layer.

[0070] In some embodiments of this application, the thermal response impedance change layer and / or catalytic active material layer can be formed by precisely applying functional slurry to a preset thermal triggering area on a conventional electrode sheet (positive or negative electrode) that has been coated and dried, through methods such as local coating, screen printing or inkjet printing, and then forming a firmly adhered functional layer after subsequent drying and rolling.

[0071] In some embodiments of this application, a two-step coating method can also be used in the electrode coating stage. First, conventional electrode slurry is coated in the non-thermal triggering area to form the main active material layer, and functional slurry is coated in the thermal triggering area. After the two are dried simultaneously, the main active material layer and the catalytic active material layer are formed.

[0072] In some embodiments of this application, a conventional electrode slurry can be coated on the battery electrode to form a main active material layer. Then, a functional slurry is coated on the heat-triggered area of ​​the wet active material layer. After both are dried simultaneously, the catalytic active material layer is partially embedded and tightly bonded to the surface of the active material layer.

[0073] In some embodiments of this application, conductive fillers and thermally responsive polymer matrices can be dispersed in a suitable solvent (such as N-methylpyrrolidone, deionized water, etc.) in a set ratio, and a uniform, stable functional coating slurry with suitable viscosity and rheological properties can be formed by high-speed stirring, ball milling or ultrasonic treatment.

[0074] In some embodiments of this application, the battery electrode fabrication process is highly compatible with traditional battery electrode manufacturing lines. Only an auxiliary precision slit coating head, spraying system, or printing device needs to be integrated into existing coating equipment for the heat-triggered area to achieve precise and selective coating. No major modifications to core equipment such as ovens and roller presses are required, resulting in low process modification costs and easy implementation of large-scale production and quality control.

[0075] In some implementations, the thermally triggered region occupies 10-50% of the total area of ​​the battery electrode.

[0076] In some embodiments of this application, the thermal triggering region occupies 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, etc., of the total area of ​​the battery electrode. Thermal runaway triggering is a transient process involving complex chemical reactions and heat transfer. If the thermal triggering region is designed to be too small (e.g., <10%), the initial heat generated may be absorbed and dissipated by the surrounding non-thermal triggering region, leading to failure or delay in thermal runaway triggering. An area of ​​10% or more can provide sufficient thermal mass and reactant mass to ensure the triggering of thermal runaway. By controlling the area of ​​the thermal triggering region to within 50%, it is ensured that at least half of the electrode area is high-performance active material, thereby limiting the potential negative impact of the embodiments of this application on the total energy density of the battery to an acceptable or even negligible range.

[0077] In some implementations, the thermal triggering zone is located in a non-central area of ​​the battery electrode.

[0078] In some embodiments of this application, the battery electrode includes a central region and a non-central region. The central region is a circular area with the geometric center of the battery electrode as its center and a radius equal to a preset percentage (e.g., 20%, 30%) of the shortest side length L of the battery electrode, or a continuous central region whose area does not exceed a preset percentage (e.g., 20%, 30%) of the total area of ​​the battery electrode. The non-central region is the area on the battery electrode other than the central region.

[0079] In some embodiments of this application, the central region can be a continuous internal region on the battery electrode sheet that is more than a preset proportion (e.g., 20%, 25%, 30%, etc.) of the total size of the electrode sheet in that direction from any edge.

[0080] For example, refer to Figure 3 The battery electrode 100 includes a thermal triggering region 101 and a non-triggering region 102, wherein the thermal triggering region 101 is located in the non-central region 104 of the battery electrode 100.

[0081] In this embodiment, thermal runaway typically generates a large amount of gas within milliseconds to seconds, causing a rapid increase in pressure. If it occurs at the geometric center of the electrode sheet, the high-temperature ejected material needs to diffuse outwards, traversing the entire electrode core or stacked structure. This long path and high resistance can lead to pressure accumulation in the core area, making timely release difficult. However, this embodiment limits the thermal triggering area to the non-central region of the battery electrode sheet (such as the edge, corner, or near the tab), thereby constructing the shortest pressure relief path from the internal reaction core to the external environment.

[0082] In some implementations, refer to Figure 4 The thermal trigger zone 101 is located on the side of the battery electrode 100 near the explosion-proof valve 201.

[0083] In this embodiment, by placing the thermal trigger zone on the battery electrode side near the explosion-proof valve, it is ensured that in the event of battery abuse, the physical distance between the high-temperature, high-pressure gas and ejected material generated by the violent exothermic reaction preferentially triggered by the thermal trigger zone and the explosion-proof valve is minimized, and the path resistance is reduced. This maximizes the guarantee that the explosion-proof valve is accurately triggered and fully opened at the first moment, allowing destructive energy to be released at high speed and directionally. This fundamentally avoids internal pressure accumulation and physical rupture of the casing due to delayed pressure relief or obstructed path, as well as secondary ignition and heat spread caused by the irregular movement of high-temperature ejected material inside the battery, greatly improving the system safety and protection reliability of the battery.

[0084] In some embodiments, the battery electrode includes a positive electrode.

[0085] In this embodiment, the materials used in the battery electrodes, such as conductive fillers, thermally responsive polymer matrices, and catalytic metal elements, are all mature, low-cost industrial raw materials. Furthermore, based on the concept of localized functionalization, this embodiment introduces a special functional coating only in the thermal triggering area of ​​the electrode. This avoids dependence on expensive and scarce materials or complex components, minimizes modifications to existing mature battery manufacturing processes, and results in relatively small incremental marginal costs, laying a solid economic foundation for the large-scale commercial application of the technology. In addition, the battery electrodes in this embodiment actively guide thermal runaway to occur preferentially in a preset fixed thermal triggering area, transforming the triggering mechanism of this destructive event from unpredictable randomness to pre-set determinism. This enables the passive safety design at the battery system level (such as explosion-proof valve positioning, pressure relief channel routing, and heat insulation and cooling system arrangement) to achieve precise protection, solving the problem of off-target failure of protective measures caused by the random failure location in traditional safety designs. By coordinating the thermal trigger zone with the explosion-proof valve in the casing, the directional and orderly release of high-temperature and high-pressure products is achieved, which greatly avoids the secondary hazards caused by the disorderly accumulation of internal pressure and the random movement of ejected materials. This confines the destructive force of thermal runaway to a local area and significantly improves the battery's system safety threshold and resistance to thermal propagation.

[0086] The second aspect of this application provides a battery. The battery includes the battery electrode provided in the first aspect of this application. The function of the battery of the second aspect of this application is the same as that of the battery electrode provided in the first aspect of this application, and will not be repeated here.

[0087] In some embodiments, at least one positive electrode of the battery is the battery electrode provided in the first aspect of this application.

[0088] In some embodiments, the battery further includes: a negative electrode sheet, the negative electrode sheet including a negative electrode active material layer, the negative electrode active material layer including a negative electrode active material.

[0089] The negative electrode is a composite electrode structure that serves as the negative end in a lithium-ion battery. It typically consists of a negative current collector (such as copper foil) and a layer of negative active material coated on its surface. The negative active material layer mainly includes negative active materials, conductive agents, binders, and optionally dispersants. During the charging and discharging process of the battery, the negative electrode undertakes the insertion and extraction reactions of lithium ions and is one of the key components for realizing the storage and release of electrical energy. Its structural stability, electronic / ion conduction capacity, and interface characteristics directly affect the battery's energy efficiency, rate performance, cycle life, and safety performance.

[0090] In some embodiments, the negative electrode active material includes at least one of artificial graphite, natural graphite, soft carbon, hard carbon, and silicon-based materials.

[0091] In addition, the battery and power-consuming device of this application will be described below with appropriate reference to the accompanying drawings.

[0092] In one embodiment of this application, a battery is provided.

[0093] Typically, a battery consists of a positive electrode, a negative electrode, an electrolyte, and a separator. During charging and discharging, active ions move back and forth between the positive and negative electrodes, inserting and releasing. The electrolyte acts as a conductor between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, primarily prevents short circuits while allowing ions to pass through.

[0094] Positive electrode sheet The positive electrode can be the battery electrode of the first aspect of this application, which includes a positive current collector and a positive active material layer disposed on at least one surface of the positive current collector.

[0095] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material layer is disposed on either or both of the two opposite surfaces of the positive current collector.

[0096] In some embodiments, the positive current collector may be a metal foil or a composite current collector. For example, aluminum foil may be used as the metal foil. The composite current collector may include a polymer substrate and a metal layer formed on at least one surface of the polymer substrate. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0097] In some embodiments, the positive electrode active material layer may further include a binder. As an example, the binder may include at least one selected from polyvinylidene fluoride, styrene-butadiene rubber, polyacrylic acid, sodium polyacrylate, polyacrylamide, polyvinyl alcohol, sodium alginate, polymethacrylic acid, and carboxymethyl chitosan.

[0098] In some embodiments, the positive electrode active material layer may further include a conductive agent. As an example, the conductive agent may include at least one of acetylene black, superconducting carbon, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0099] Negative electrode sheet The negative electrode sheet may include only a negative current collector, or it may include a negative current collector and a negative active material layer disposed on at least one surface of the negative current collector, wherein the negative active material layer includes a negative active material.

[0100] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material layer is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0101] In some embodiments, the negative electrode current collector may be a metal foil or a composite current collector. For example, copper foil may be used as the metal foil. The composite current collector may include a polymer material substrate and a metal layer formed on at least one surface of the polymer material substrate. The composite current collector may be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0102] In some embodiments, the negative electrode active material may be a negative electrode active material known in the art. As an example, the negative electrode active material may include at least one of: artificial graphite, natural graphite, soft carbon, hard carbon, and silicon-based materials. However, this application is not limited to these materials, and other conventional materials that can be used as battery negative electrode active materials may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0103] electrolytes The electrolyte acts as a conductor of ions between the positive and negative electrodes. This application does not impose specific restrictions on the type of electrolyte; it can be selected according to requirements. For example, the electrolyte can be liquid, gel, or entirely solid.

[0104] Separating membrane In some embodiments, the battery also includes a separator. This application does not impose any particular limitation on the type of separator; any known porous separator with good chemical and mechanical stability can be selected.

[0105] In some embodiments, the material of the separator can be selected from at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation.

[0106] In some embodiments, the battery may include an outer packaging. This outer packaging may be used to encapsulate the electrode assembly and electrolyte described above.

[0107] In some implementations, the battery's outer packaging can be a hard shell, such as a hard plastic shell, an aluminum shell, or a steel shell. The battery's outer packaging can also be a soft pack, such as a pouch. The soft pack can be made of plastic, such as polypropylene, polybutylene terephthalate, and polybutylene succinate.

[0108] This application does not impose any particular limitation on the shape of the battery; it can be cylindrical, square, or any other arbitrary shape. For example, Figure 1 This is a square-shaped battery as an example.

[0109] In addition, this application also provides an electrical device, which includes at least one of the battery electrode and battery provided in this application. The battery can be used as a power source for the electrical device or as an energy storage unit of the electrical device. The electrical device may include, but is not limited to, mobile devices (such as mobile phones, laptops, etc.), electric vehicles (such as pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc.

[0110] As an electrical device, the battery can be selected according to its usage requirements.

[0111] As an example, the electrical device can be a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle. To meet the high power and high energy density requirements of the battery for this electrical device, a battery pack or battery module can be used.

[0112] Another example device could be a mobile phone, tablet, or laptop. These devices typically require a slim and lightweight design and can be powered by a battery.

[0113] The following describes embodiments of this application. The embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially.

[0114] Example 1 (1) Positive electrode plate; The positive electrode is provided with region a as a non-thermal triggering region and region b as a thermal triggering region. Region b is provided with a catalytic active material layer, and the catalytic metal element in the catalytic active material layer is Fe. The Fe content in region b is 3000 PPM higher than that in region a.

[0115] (2) Negative electrode plate; (3) Electrolyte system; In addition to the materials mentioned above, the battery cell also includes a separator, an aluminum-plastic film, and tabs. All materials are assembled into a battery cell.

[0116] The assembled battery cells were subjected to overcharge abuse tests, and the temperature rise behavior in different internal regions was monitored. The results were referenced... Figure 6 As shown, the horizontal axis represents time (in seconds), ranging from 0 to 1100 seconds; the left vertical axis represents temperature (in degrees Celsius), ranging from 0 to 180 degrees Celsius; and the right vertical axis represents cell voltage (in V), ranging from 0 to 6.0 V. The graph includes the temperature change trends in regions a and b, and the overall cell voltage change over time. Figure 6 It can be seen that in the initial stage of overcharging (0~600 s), the temperature rise of regions a and b is gradual and similar; however, in the middle and late stages of overcharging (i.e., after 600 s), the temperature of region b begins to rise sharply, significantly exceeding that of region a. This is because region b contains a catalytically active material layer, and its Fe content is 3000 PPM higher than that of region a. Consequently, under the high pressure and high temperature environment caused by overcharging, it significantly accelerates the exothermic side reactions such as electrolyte decomposition and / or oxygen release from the cathode material. This allows the temperature of region b to reach and exceed the triggering critical temperature for battery thermal runaway (e.g., >180℃) first, meaning that thermal runaway is ultimately preferentially triggered in region b.

[0117] In summary, the battery electrodes in this application actively guide thermal runaway to occur preferentially in a preset fixed thermal triggering zone, transforming the triggering mechanism of this destructive event from unpredictable randomness to pre-set determinism. This enables passive safety designs at the battery system level (such as explosion-proof valve positioning, pressure relief channel routing, and heat insulation and cooling system layout) to achieve precise protection, solving the problem of protection measures failing to target due to random failure locations in traditional safety designs.

[0118] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A battery electrode, characterized in that, include: At least one hot-trigger zone; Under battery abuse conditions, the thermal trigger zone triggers thermal runaway before other areas of the battery electrode.

2. The battery electrode as described in claim 1, characterized in that, The thermal triggering zone is provided with a thermal response impedance change layer and / or a catalytically active material layer.

3. The battery electrode as described in claim 2, characterized in that, Under battery abuse conditions, the resistivity of the thermally responsive impedance-changing layer increases by at least 100%. And / or, the thermally responsive impedance change layer comprises: a thermally conductive filler and a thermally responsive polymer matrix.

4. The battery electrode as described in claim 3, characterized in that, The thermally conductive filler includes at least one of conductive carbon black, graphene, and carbon nanotubes. And / or, the thermally responsive polymer matrix includes at least one of: polyacrylic acid, polyvinylidene fluoride, polyvinylidene fluoride copolymer, polystyrene, styrene-butadiene rubber, and thermoplastic polyurethane elastomer; And / or, the amount of the thermally conductive filler added is 3~95 wt.%.

5. The battery electrode as described in claim 2, characterized in that, The content of catalytic metal elements in the catalytic active material layer is higher than the content of catalytic metal elements in other regions of the battery electrode. And / or, the catalytic metal element includes at least one of iron, titanium, copper and manganese; And / or, the content of catalytic metal elements in the catalytic active material layer is 200~10000 PPM higher than the content of catalytic metal elements in other regions of the battery electrode.

6. The battery electrode sheet according to any one of claims 1 to 5, characterized in that, The thermal triggering zone occupies 10-50% of the total area of ​​the battery electrode.

7. The battery electrode sheet according to any one of claims 1 to 5, characterized in that, The thermal triggering zone is located on the side of the battery electrode near the explosion-proof valve; And / or, the thermal triggering zone is located in the non-central area of ​​the battery electrode.

8. The battery electrode sheet according to any one of claims 1 to 5, characterized in that, The battery electrode includes: a positive electrode.

9. A battery, characterized in that, Includes the battery electrode as described in any one of claims 1 to 8.

10. An electrical device, characterized in that, It includes the positive electrode sheet as described in any one of claims 1 to 8, or the battery as described in claim 8.

Images