Battery cell, battery, and electric device

Abstract

This application provides a battery cell, a battery, and an electrical device, belonging to the field of battery technology. The battery cell includes at least one first electrode core and at least one second electrode core. At least one internal component of the first electrode core is enriched with a lithium replenishing agent. Under abuse conditions, the first electrode core triggers thermal runaway before the second electrode core. This application, by adding a lithium replenishing agent to at least one first electrode core, causes it to trigger thermal runaway before the second electrode core under abuse conditions, thereby sequentially and dispersed the heat and gas generation of the chain side reaction, avoiding serious safety accidents such as poor venting and explosions / fires caused by synchronous failure.

Description

Technical Field

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

[0002] As the capacity and size of large-capacity energy storage cells increase, their thermal safety performance deteriorates. In single-cell batteries such as lithium iron phosphate, when subjected to abuse conditions, heat rapidly accumulates inside the battery. The separator layer shrinks or melts due to heat, causing direct contact and short circuits between the positive and negative electrodes, triggering a chain reaction that quickly evolves into overall thermal runaway. Especially in system-level thermal runaway testing, when thermal runaway is triggered under abuse conditions, the failure time between the individual electrodes within the cell is highly concentrated, with heat generation and gas generation occurring simultaneously. This makes it highly susceptible to serious safety accidents such as explosions and fires due to poor venting. Therefore, how to effectively delay or avoid catastrophic thermal runaway caused by overheating in large-capacity cells is a pressing technical problem that needs to be solved. Summary of the Invention

[0003] This application provides a battery cell, battery, and power device that, by adding a lithium supplement to at least one first electrode core, causes it to trigger thermal runaway before the second electrode core under abuse conditions, thereby sequentially and disperses the heat and gas generation of the chain side reaction, avoiding serious safety accidents such as poor venting and explosions and fires caused by synchronous failure.

[0004] To achieve the above objectives, the first aspect of this application provides a battery cell comprising: at least one first electrode core and at least one second electrode core, wherein at least one internal component of the first electrode core is provided with a lithium replenishing agent, and under abuse conditions, the first electrode core triggers thermal runaway before the second electrode core.

[0005] In the technical solution of this application, a battery cell is provided, comprising: at least one first electrode core and at least one second electrode core. At least one internal component of the first electrode core is provided with a lithium replenishing agent, which enables the lithium replenishing agent added to the first electrode core to rapidly release active lithium when the battery cell is subjected to abuse conditions such as overcharging, overheating, and short circuit. This active lithium induces or exacerbates a series of exothermic side reactions, thereby significantly increasing the heat generation of the first electrode core. As a result, it reaches the thermal runaway trigger condition preferentially over the second electrode core during the temperature rise process. Thus, before the overall thermal runaway of the battery cell fully erupts, the early heat generation and gas generation behavior of the first electrode core triggers the battery management system or protection device to respond in advance (e.g., timely stop charging or disconnect the circuit). This disperses and sequences the energy release process of the chain side reactions inside the battery cell, effectively avoiding serious safety accidents such as poor venting, concentrated heat accumulation, and explosions and fires caused by the simultaneous failure of multiple electrode cores, and significantly improving the thermal safety performance of large-capacity battery cells under abuse conditions.

[0006] In some implementations, under abuse conditions, the time difference between the first electrode core and the second electrode core triggering thermal runaway is greater than or equal to 10 s.

[0007] In some embodiments, the internal components in which the lithium replenishing agent is added to the first electrode core include at least one of a positive electrode, a negative electrode, and a separator.

[0008] In some implementations, the amount of lithium supplementation agent added to the positive electrode sheet in the first electrode core is greater than 0% and less than 20% by mass percentage.

[0009] In some implementations, the amount of lithium supplementation agent added to the positive electrode sheet in the first electrode core is greater than 0% and less than or equal to 10% by mass percentage.

[0010] In some implementations, the amount of lithium replenishing agent added to the negative electrode sheet in the first electrode core is greater than 0% and less than 10% by mass percentage.

[0011] In some implementations, the amount of lithium supplementer added to the negative electrode sheet in the first electrode core is greater than 0% and less than or equal to 5% by mass percentage.

[0012] In some embodiments, the lithium replenishing agent includes at least one of metallic lithium, lithium-containing inorganic compounds, and lithium-containing organic compounds.

[0013] In some embodiments, the cell has a thickness greater than or equal to 46 mm and a capacity greater than or equal to 300 Ah.

[0014] A second aspect of this application provides a battery comprising the cell described above.

[0015] A third aspect of this application provides an electrical device, including at least one of the battery cell of the first aspect of this application and the battery of the second aspect of this application. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a battery cell according to an embodiment of this application; Figure 2 This is a schematic diagram of a battery according to an embodiment of this application; Figure 3 This is a schematic diagram of an energy storage device according to an embodiment of this application; Figure 4 This is a schematic diagram of an embodiment of the power supply system of this application.

[0017] Explanation of reference numerals in the attached figures 100. Battery cell; 110. First electrode core; 120. Second electrode core; 111. Positive electrode plate; 112. Negative electrode plate; 113. Diaphragm. Detailed Implementation

[0018] The following detailed description, with appropriate reference to the accompanying drawings, specifically discloses embodiments of the battery cell, 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.

[0019] 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 also 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 "a~b" 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.

[0020] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0021] 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.

[0022] In conventional technologies, when lithium iron phosphate (LFP) batteries are subjected to abuse conditions, heat rapidly accumulates inside the battery. The separator layer shrinks or melts due to heat, causing a short circuit between the positive and negative electrodes, triggering a chain reaction that quickly evolves into overall thermal runaway. Especially in system-level thermal runaway testing, when thermal runaway is triggered under abuse conditions, the failure time between the individual electrodes within the cell is highly concentrated, with heat and gas generation occurring simultaneously. This makes it highly susceptible to serious safety accidents such as explosions and fires due to poor venting. Therefore, effectively delaying or avoiding catastrophic thermal runaway caused by overheating in high-capacity battery cells is a pressing technical problem that needs to be solved.

[0023] Based on this, this application proposes a battery cell comprising at least one first electrode core and at least one second electrode core. At least one internal component of the first electrode core is supplemented with a lithium replenishing agent, which enables the lithium replenishing agent added to the first electrode core to rapidly release active lithium when the battery cell encounters abuse conditions such as overcharging, overheating, or short circuits. This active lithium induces or exacerbates a series of exothermic side reactions, thereby significantly increasing the heat generation of the first electrode core. As a result, it reaches the thermal runaway trigger condition preferentially over the second electrode core during the temperature rise process. Thus, before the overall thermal runaway of the battery cell fully erupts, the early heat generation and gas generation behavior of the first electrode core triggers the battery management system or protection device to respond in advance (e.g., timely stop charging or disconnect the circuit). This disperses and sequences the energy release process of the chain of side reactions inside the battery cell, effectively avoiding serious safety accidents such as poor venting, concentrated heat accumulation, and explosions and fires caused by the simultaneous failure of multiple electrode cores. This significantly improves the thermal safety performance of large-capacity battery cells under abuse conditions.

[0024] The first aspect of this application provides a battery cell, as shown in the reference... Figure 1 The battery cell 100 includes at least one first electrode 110 and at least one second electrode 120. At least one internal component of the first electrode 110 is filled with a lithium replenishing agent. Under abuse conditions, the first electrode 110 triggers thermal runaway before the second electrode 120.

[0025] Abuse conditions refer to a series of extreme test conditions or unexpected operating conditions that can cause irreversible performance degradation or safety failure of the cell 100 or battery. These conditions are sufficient to trigger a self-accelerating exothermic reaction chain inside the cell 100 or battery, i.e., thermal runaway.

[0026] In one feasible embodiment, at least one internal component of the first electrode core 110 is supplemented with a lithium replenishing agent. Under abuse conditions, the lithium replenishing agent added to the first electrode core 110 can rapidly release active lithium, which induces or exacerbates a series of exothermic side reactions, such as SEI film decomposition, reaction between the negative electrode 112 and the electrolyte, and reaction between the negative electrode 112 and the binder. This significantly increases the heat generation of the first electrode core 110, causing it to reach the thermal runaway trigger condition preferentially over the second electrode during temperature rise, thus achieving the effect of localized preferential thermal runaway. The battery cell 100 can rapidly trigger thermal runaway in the early stages of abuse conditions through the early heat generation of the first electrode core 110, thereby timely stopping charging or activating the protection mechanism. This prevents heat from accumulating simultaneously in all electrode cores, causing poor venting and explosion / fire, ultimately significantly improving the thermal safety performance of the battery cell 100 under abuse conditions.

[0027] In one feasible implementation, under abuse conditions, the time difference between the first and second electrode cores triggering thermal runaway is greater than or equal to 10 s.

[0028] Optionally, under abuse conditions, the first electrode core will trigger thermal runaway before the second electrode core, and the time difference between the two triggering thermal runaway can be greater than or equal to 10 s, 15 s, 20 s, 25 s, 30 s, etc., thereby avoiding the simultaneous accumulation of heat in all electrode cores, which could lead to poor exhaust and explosion / fire.

[0029] Optionally, the abuse conditions include at least one of the following: electrical abuse, thermal abuse, and mechanical abuse.

[0030] Optionally, 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.

[0031] Optionally, thermal abuse refers to an abnormal increase in the ambient temperature or local temperature of the battery, including external heating and / or local overheating.

[0032] Alternatively, 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.

[0033] Optionally, the amount of lithium supplementer added to the second electrode core 120 is less than that to the first electrode core 110.

[0034] Optionally, the second electrode core 120 is not supplemented with lithium replenishment agent.

[0035] In this embodiment, differentiated lithium replenishment ensures that, under abuse conditions, the first electrode core 110 triggers thermal runaway before the second electrode core 120.

[0036] In one feasible embodiment, the internal components of the first electrode core 110 with added lithium replenishing agent include at least one of: positive electrode 111, negative electrode 112 and separator 113.

[0037] The positive electrode 111 serves as a carrier for lithium-ion intercalation and deintercalation reactions during battery charging and discharging, and conducts electrons to the external circuit through the positive electrode current collector. It is a core internal component that determines the battery's energy density, power performance, and cycle stability.

[0038] The negative electrode 112 serves as a carrier for lithium-ion insertion and extraction during battery charging and discharging, and conducts electrons to the external circuit through the negative electrode current collector. It is a core internal component that determines the battery's energy density, rate performance, and cycle stability.

[0039] The separator 113 inside the battery serves to isolate the positive and negative electrode plates 112 to prevent electronic short circuits, while also providing ion conduction channels. It is a core internal component that determines the battery's safety performance, internal resistance, and cycle life.

[0040] Optionally, the lithium supplement can be added at at least one of the following locations: inside the positive active material layer of the positive electrode 111, on the surface of the positive active material layer, on the surface of the positive current collector (aluminum foil), in the undercoating layer between the positive current collector and the active material layer, and in the functional coating (such as conductive coating or ceramic coating) on ​​the surface of the positive electrode 111.

[0041] Optionally, the lithium supplement can be added at at least one of the following locations: inside the negative electrode active material layer of the negative electrode 112, on the surface of the negative electrode active material layer, on the surface of the negative electrode current collector (copper foil), in the undercoating layer between the negative electrode current collector and the active material layer, and in the functional coating on the surface of the negative electrode 112.

[0042] Optionally, the lithium supplement can be added at at least one of the following locations: inside the substrate body (such as a polyolefin porous membrane) of the separator 113, in the ceramic coating on one or both sides of the separator 113, in the adhesive coating on one or both sides of the separator 113, and in other functionally modified coatings on the surface of the separator 113.

[0043] In one feasible embodiment, the amount of lithium supplementer added to the positive electrode 111 in the first electrode core 110 is greater than 0% and less than 20% by mass percentage.

[0044] Optionally, the amount of lithium supplementer added to the positive electrode 111 in the first electrode core 110 by weight percentage is 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 19.5%, etc.

[0045] Optionally, the amount of lithium supplement added to the positive electrode 111 refers to the percentage of the mass of the positive electrode lithium supplement to the mass of the positive electrode active material in the positive electrode 111.

[0046] In one feasible embodiment, the amount of lithium supplementer added to the positive electrode 111 in the first electrode core 110 is greater than 0% and less than or equal to 10% by mass percentage.

[0047] In one feasible embodiment, the amount of lithium supplementer added to the negative electrode 112 in the first electrode core 110 is greater than 0% and less than 10% by mass percentage.

[0048] Optionally, the amount of lithium supplementer added to the negative electrode 112 in the first electrode core 110 by weight percentage is 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 9.5%, etc.

[0049] Optionally, the amount of lithium supplement added to the negative electrode 112 refers to the percentage of the mass of the negative electrode lithium supplement to the mass of the negative electrode active material in the negative electrode 112.

[0050] In one feasible embodiment, the amount of lithium supplementer added to the negative electrode 112 in the first electrode core 110 is greater than 0% and less than or equal to 5% by mass percentage.

[0051] Optionally, the amount of lithium supplementer added to the positive electrode 111 in the second electrode core 120 is less than 1%, 0.5%, 0.1%, 0.05%, 0.01%, etc., by mass percentage.

[0052] Optionally, the amount of lithium supplementer added to the negative electrode 112 in the second electrode core 120 is less than 1%, 0.5%, 0.1%, 0.05%, 0.01%, etc., by mass percentage.

[0053] It is understandable that the positive electrode 111 typically uses lithium-containing compounds as lithium replenishing agents (such as Li2NiO2, Li5FeO4, etc.). These compounds have relatively low specific capacity, and in order to release sufficient active lithium under abuse conditions to drive the first electrode core 110 to trigger the chain side reaction in advance, a relatively large mass proportion needs to be added. On the other hand, the negative electrode 112 typically uses elemental lithium metal (such as lithium powder, lithium foil) as the lithium replenishing source. The theoretical specific capacity of metallic lithium is as high as 3860 mAh / g, which is much higher than that of the positive electrode lithium replenishing compound. Therefore, only a very small amount needs to be added to generate an equal amount or even more active lithium to induce preferential thermal runaway. Therefore, due to the significant difference in the specific capacity of the lithium replenishing agents themselves, the mass proportion of lithium replenishing agents required to achieve the same timing triggering function in the positive electrode 111 and the negative electrode 112 are different.

[0054] In this embodiment, if the amount of lithium replenishing agent added to the positive electrode 111, negative electrode 112, and / or separator 113 in the first electrode core 110 is too low, the active lithium released under abuse conditions will be insufficient, making it difficult to induce or accelerate exothermic side reactions such as SEI film decomposition and negative electrode reaction with electrolyte / binder in the first electrode core 110. This results in a small time difference between the thermal runaway triggering of the first electrode core 110 and the unreplenished second electrode core 120, or even synchronous failure, making it difficult to achieve the sequential and dispersed generation of heat and gas. The risk of poor venting and explosion / fire still exists. Conversely, if the amount of lithium replenishing agent added is too high, the first electrode core 110 may experience abnormal heat generation, gas expansion, or micro-short circuits prematurely due to local lithium excess under normal battery charge and discharge conditions, leading to the deterioration of the normal cycle performance of the cell 100, or even unexpected thermal runaway in the early stages of its service life. Therefore, the amount of lithium replenishing agent added in this application embodiment is controlled within a reasonable range to ensure that the first electrode core 110 can reliably trigger thermal runaway before the second electrode core 120 under the target abuse conditions, while not impairing the safety and cycle stability of the cell 100 under normal use conditions.

[0055] In one feasible embodiment, the lithium replenishing agent includes at least one of lithium metal, lithium-containing inorganic compounds, and lithium-containing organic compounds.

[0056] Optionally, the lithium metal includes at least one of the following: lithium foil, copper-lithium composite sheet, stabilized lithium metal powder, and ultrathin lithium foil.

[0057] Optionally, the lithium-containing inorganic compounds include: lithium peroxide, lithium oxide, lithium sulfide, lithium nitride, lithium-rich nickel oxide, lithium-rich ferric oxide, lithium-rich cobalt oxide, lithium-rich manganese-based materials, lithium-rich disordered rock salt oxides, and Li. 1+x At least one of Mn2O4, lithium-rich ternary materials, lithium aluminum hydride, and lithium borohydride.

[0058] Optionally, the lithium-containing organic compound includes at least one of lithium oxalate, Li2DHBN, lithium formate, butyllithium, lithium naphthylene, and lithium biphenyl.

[0059] Optionally, when replenishing lithium on the positive electrode 111, compounds that can irreversibly decompose and release active lithium during charging can be selected. These mainly include lithium-containing inorganic compounds (such as lithium peroxide, lithium oxide, lithium sulfide, lithium nitride, lithium-rich nickel acid, lithium-rich iron acid, lithium-rich cobalt acid, lithium-rich manganese-based materials, and lithium-rich disordered rock salt oxides) and some lithium-containing organic compounds (such as lithium oxalate, Li2DHBN, and lithium formate). These lithium replenishing agents are added directly during positive electrode slurry preparation or mixing, and decompose to release lithium ions under initial or abuse conditions to compensate for the lithium consumed by the formation of the negative electrode SEI film or side reactions, or to induce preferential thermal runaway under abuse conditions. In addition, electrochemical methods (using metallic lithium as the counter electrode to over-lithiplegate the positive electrode material) and chemical synthesis methods (using lithium-containing organic solutions to soak the positive electrode) are also methods for replenishing lithium on the positive electrode. The former involves the use of metallic lithium, while the latter involves organic lithium reagents (such as lithium naphthalene).

[0060] Optionally, when replenishing lithium on the negative electrode 112, lithium replenishing agents that can directly provide active lithium to the negative electrode or insert lithium ions through chemical reactions can be selected. These mainly include metallic lithium (lithium sheets, copper-lithium composite sheets, stabilized lithium metal powder, ultra-thin metallic lithium foil) and some lithium-containing inorganic compounds (such as lithium aluminum hydride, lithium borohydride) and lithium-containing organic compounds (such as butyllithium, naphthalene lithium, biphenyl lithium). Lithium replenishment on the negative electrode 112 can be achieved through physical lithium replenishment, i.e., using metallic lithium powder or lithium foil, and spontaneously replenishing lithium through rolling or liquid injection; it can also be achieved through chemical lithium replenishment, i.e., using lithium-containing reducing agents (organic lithium such as butyllithium, naphthalene lithium, biphenyl lithium, or lithium hydride such as lithium aluminum hydride, lithium borohydride) to prepare a solution, and inserting lithium into the negative electrode through soaking or spraying; or, electrochemical lithium replenishment or self-discharge lithium replenishment, using metallic lithium as the lithium source, and achieving lithium replenishment by introducing a third electrode discharge or short-circuit contact, respectively.

[0061] In one feasible embodiment, the thickness of the cell 100 is greater than or equal to 46 mm and the capacity is greater than or equal to 300 Ah.

[0062] In one feasible embodiment, as the thickness and capacity of the energy storage cell 100 continue to increase, the heat accumulation effect inside the cell 100 is significantly aggravated. Under abuse conditions, the thermal coupling between the cores becomes tighter, leading to the synchronous triggering of chain side reactions and highly concentrated heat and gas generation. This makes it extremely easy to cause serious safety accidents such as explosions and fires due to poor exhaust. However, for the cell 100 with a smaller thickness or lower capacity, its heat diffusion path is shorter and its heat dissipation conditions are relatively superior. Even without adopting the timing triggering strategy of the present invention, the failure time difference between the cores is sufficient to naturally disperse heat and gas, and the risk of synchronous thermal runaway is low.

[0063] In this embodiment, a battery cell 100 is provided, including at least one first electrode core 110 and at least one second electrode core 120. At least one internal component of the first electrode core 110 is enriched with a lithium replenishing agent, so that when the battery cell 100 encounters abuse conditions such as overcharging, overheating, or short circuit, the lithium replenishing agent added to the first electrode core 110 can quickly release active lithium. This active lithium will induce or exacerbate a series of exothermic side reactions, thereby significantly increasing the heat generation of the first electrode core 110, causing it to reach the thermal runaway trigger condition preferentially before the second electrode core during the temperature rise process. Thus, before the overall thermal runaway of the cell 100 fully erupts, the early heat and gas generation behavior of the first electrode core 110 triggers the battery management system or protection device to respond in advance (e.g., to stop charging or disconnect the circuit in time). This disperses and sequences the energy release process of the chain reaction inside the cell 100, effectively avoiding serious safety accidents such as poor venting, concentrated heat accumulation, and explosions and fires caused by the simultaneous failure of multiple electrode cores. This significantly improves the thermal safety performance of the large-capacity cell 100 under abuse conditions.

[0064] This application provides a second aspect of a battery. The battery includes the cell provided in the first aspect of this application. The battery of the second aspect of this application functions similarly to the cell provided in the first aspect of this application. Other technical features of this battery are the same as those disclosed in the methods of the above embodiments, and will not be repeated here.

[0065] A third aspect of this application provides an electrical device. The electrical device includes the battery cell provided in the first aspect of this application, or the battery provided in the second aspect of this application. The function of the electrical device of the third aspect of this application can be referred to the function of the battery cell provided in the first aspect of this application. Other technical features of this electrical device are the same as those disclosed in the methods of the above embodiments, and will not be repeated here.

[0066] In addition, the battery and power supply device of this application will be described below with appropriate reference to the accompanying drawings.

[0067] In one embodiment of this application, a battery is provided.

[0068] Typically, a battery includes a cell, specifically the cell provided in the first aspect of this application. The cell includes at least one first electrode and at least one second electrode, each comprising a positive electrode, a negative electrode, an electrolyte, and a separator. During charging and discharging, active ions repeatedly insert and extract between the positive and negative electrode. The electrolyte acts as a conductor between the positive and negative electrode. The separator, positioned between the positive and negative electrode, primarily prevents short circuits between the positive and negative electrodes while allowing ions to pass through.

[0069] Positive electrode sheet The positive electrode sheet may include a positive current collector and a positive active material layer disposed on at least one surface of the positive current collector.

[0070] 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.

[0071] 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.).

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.).

[0077] 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.

[0078] 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.

[0079] diaphragm 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.

[0080] In some embodiments, the diaphragm material may be selected from at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The diaphragm may be a single-layer film or a multi-layer composite film, without particular limitation. When the diaphragm is a multi-layer composite film, the materials of each layer may be the same or different, without particular limitation.

[0081] 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.

[0082] 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.

[0083] 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 2 This is a square-shaped battery as an example.

[0084] In addition, this application also provides an electrical device, which includes at least one of the battery cell 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 for 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.

[0085] As an electrical device, the battery can be selected according to its usage requirements.

[0086] Optionally, refer to Figure 3 The electrical device can be an energy storage device. The energy storage device can adopt an integrated structure of cabinet or container and can be deployed independently outdoors or indoors as a backup power source or peak shaving and frequency regulation equipment.

[0087] Optionally, refer to Figure 4 The electrical device can be applied to an electrical system that can integrate new energy power generation equipment (such as wind turbines and photovoltaic modules), the electrical device (i.e., energy storage device) of the present application embodiment, and the load.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] Example 1 A bipolar stacked battery is provided, the battery including a cell, the cell including a first electrode and a second electrode, the cell thickness is 55 mm, and the capacity is 650 Ah; by weight percentage, 1% of lithium-rich iron acid (Li5FeO4 / LFO) is added to the positive electrode of the first electrode as a lithium replenishing agent, while no lithium replenishing agent is added to the second electrode. In addition, the positive electrode, negative electrode and separator of the first electrode and the second electrode are identical.

[0092] Example 2 The difference from Example 1 is that 2% lithium-rich ferric acid (Li5FeO4 / LFO) is added to the positive electrode of the first electrode core as a lithium replenishing agent.

[0093] Example 3 The difference from Example 1 is that 5% lithium-rich ferric acid (Li5FeO4 / LFO) is added to the positive electrode of the first electrode core as a lithium replenishing agent.

[0094] Example 4 The difference from Example 1 is that 2% lithium oxide (Li2O) is added to the positive electrode of the first electrode core as a lithium supplement agent.

[0095] Example 5 The difference from Example 1 is that no lithium replenishing agent was added to the positive electrode of the first electrode core, while 3% lithium powder was added to the negative electrode as a lithium replenishing agent.

[0096] Comparative Example 1 The difference from Example 1 is that the positive electrode, negative electrode and separator of the first electrode core and the second electrode core are the same, and no lithium replenishing agent is added.

[0097] Comparative Example 2 The difference from Example 1 is that 20% lithium-rich ferric acid (Li5FeO4 / LFO) is added to the positive electrode of the first electrode core as a lithium replenishing agent.

[0098] Comparative Example 3 The difference from Example 1 is that no lithium replenishing agent was added to the positive electrode of the first electrode core, while 10% lithium powder was added to the negative electrode as a lithium replenishing agent.

[0099] The batteries of Examples 1-5 and Comparative Examples 1-3 were placed under abuse test conditions until the monitored temperature reached 3°C / s. The results are shown in Table 1 below: Table 1

[0100] According to the above experimental results, conventional batteries without added lithium additive (Comparative Example 1) and batteries with added excessive lithium additive (Comparative Examples 2 and 3) experienced deflagration. However, the embodiments of this application add lithium additive to the first electrode core, causing it to trigger thermal runaway before the second electrode core under abuse conditions, thereby making the heat and gas generation of the chain side reaction sequential and dispersed, thus avoiding deflagration.

[0101] 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 cell, characterized in that, include: At least one first electrode core and at least one second electrode core, wherein at least one internal component of the first electrode core is supplemented with lithium replenishing agent, and under abuse conditions, the first electrode core triggers thermal runaway before the second electrode core.

2. The battery cell as described in claim 1, characterized in that, Under abuse conditions, the time difference between the first electrode core and the second electrode core triggering thermal runaway is greater than or equal to 10 s.

3. The battery cell as described in claim 1, characterized in that, The internal components of the first electrode core containing the lithium replenishing agent include at least one of a positive electrode, a negative electrode, and a separator.

4. The battery cell as described in claim 3, characterized in that, By mass percentage, the amount of lithium supplementer added to the positive electrode sheet in the first electrode core is greater than 0% and less than 20%. And / or, the amount of lithium replenishing agent added to the negative electrode sheet in the first electrode core is greater than 0% and less than 10%.

5. The battery cell as described in claim 4, characterized in that, The amount of lithium supplementer added to the positive electrode sheet in the first electrode core is greater than 0% and less than or equal to 10% by mass percentage.

6. The battery cell as described in claim 4, characterized in that, The amount of lithium replenishing agent added to the negative electrode sheet in the first electrode core is greater than 0% and less than or equal to 5% by mass percentage.

7. The battery cell according to any one of claims 1 to 6, characterized in that, The lithium supplement includes at least one of metallic lithium, lithium-containing inorganic compounds, and lithium-containing organic compounds.

8. The battery cell according to any one of claims 1 to 6, characterized in that, The thickness of the battery cell is greater than or equal to 46 mm, and the capacity is greater than or equal to 300 Ah.

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

10. An electrical device, characterized in that, Includes the battery cell as described in any one of claims 1 to 8, or the battery as described in claim 9.

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