System for poisoning lithium secondary batteries, and lithium secondary battery deactivated by same

Abstract

The present invention provides a system for poisoning lithium secondary batteries, and a lithium secondary battery deactivated by same. The system for poisoning lithium secondary batteries has a poisoning agent disposed inside or outside an electrochemical reaction system of a lithium secondary battery. When the temperature of the lithium secondary battery rises to a poisoning start temperature or the voltage of the lithium secondary battery rises to a poisoning start voltage, the poisoning agent starts to release a main poisoning element and an auxiliary poisoning element into the electrochemical reaction system of the lithium secondary battery so as to deprive a positive electrode active material of the capability of participating in an electrochemical reaction involving lithium ion transfer, and stable lithium chloride (LiCl) is formed at a negative electrode end, thereby effectively inhibiting the thermal runaway of the lithium secondary battery.

Description

Lithium secondary battery poisoning system and its disabled lithium secondary batteries Technical Field

[0001] This invention relates to the safety of lithium secondary batteries, and more particularly to a lithium secondary battery poisoning system and its failure by stabilizing the crystal structure of the positive electrode active material and the highly active lithium component of the negative electrode. Background Technology

[0002] Recyclable lithium-ion batteries (such as lithium-ion or lithium-metal batteries) have become the preferred energy supply core in various devices due to their excellent electrochemical characteristics. However, in terms of the basic structure of lithium-ion batteries, the excessive extraction of lithium ions from the positive electrode active material and their subsequent deposition on the negative electrode, as well as excessive embedding or alloying in the negative electrode active material, all place the positive and negative electrode active materials in an extremely thermally unstable state. Coupled with rapid exothermic reactions, such as the decomposition of organic electrolytes, or unpredictable external factors like punctures and external short circuits, these factors can cause thermal runaway in a very short time, leading to an explosion. Therefore, solving the problem of thermal runaway has become a crucial issue in the application of lithium-ion batteries.

[0003] Currently, methods for suppressing thermal runaway can be categorized into two types based on the location of the safety mechanism reaction: those occurring outside the lithium-ion battery and those occurring inside. External methods primarily utilize digital simulation monitoring systems, while internal methods can be further divided into physical and chemical approaches. External digital monitoring systems employ various technologies, such as dedicated protection circuits and management systems, to enhance safety monitoring during battery use. Physical methods within the lithium-ion battery include thermal shutdown separators, which seal the pores of the separator when the battery cell overheats abnormally, blocking ion passage. Chemical methods within the lithium-ion battery can be categorized into degree-control types and electrochemical reaction types. Degree-control types include adding flame retardants to the electrolyte to control the degree of thermal runaway. Examples of electrochemical reaction types include: 1. Adding monomers or oligomers to the electrolyte causes polymerization as the temperature rises, reducing ion migration and decreasing ionic conductivity with increasing temperature, thus slowing down the electrochemical reaction rate in the lithium secondary battery. 2. Sandwiching a positive temperature coefficient thermistor (PTC) material between the positive or negative electrode layer and the adjacent current collector layer. As the temperature of the lithium secondary battery increases, the electronic insulation capacity increases, reducing the electron transfer capacity between the positive or negative electrode layer and the adjacent current collector layer, thereby slowing down the electrochemical reaction rate. 3. Adding additives to the electrolyte or performing surface treatments on the active material, whether the additives or surface treatments are inorganic additives containing sulfur, phosphorus, carbonic acid, or halogens, forms a modification layer on the surface of the active material after formation, thereby improving the thermal and structural stability of the active material.

[0004] However, the methods described above only passively block or inhibit the electron or ion conduction pathways in the electrochemical reaction, without addressing the fundamental issue of thermal runaway—namely, inhibiting thermal runaway of the active material. For example, the aforementioned modification layer is formed during the formation stage, and to avoid affecting the subsequent charge and discharge performance of the lithium secondary battery, the thickness of this modification layer is often only 10 to 50 nanometers. Furthermore, to avoid excessively thick modification layers affecting the electrical characteristics of the lithium secondary battery (such as charge and discharge capacity, mainly because a thick passivation layer can affect ion migration and charge transfer), the dosage of these additives is also limited to the amount required to form a modification layer of 10 to 50 nanometers. Although such a thin passivation layer containing specific elements or compounds can increase the thermal stability temperature of the active material, as the temperature rises, the extremely thin nanoscale modification layer will still break down, exposing part of the active material. Therefore, at the positive electrode, because the lattice of the positive electrode active material is unstable, oxygen will still be released, resulting in a violent thermal runaway reaction at this higher temperature.

[0005] In view of this, the present invention proposes a novel lithium secondary battery poisoning system and its disabled lithium secondary battery to effectively solve the above problems. Summary of the Invention

[0006] The main objective of this invention is to provide a lithium secondary battery poisoning system and a disabled lithium secondary battery. When the temperature of the lithium secondary battery rises to a poisoning initiation temperature or the voltage rises to a poisoning initiation voltage, the poisoning initiation temperature being approximately in the range of 120°C to 200°C and the poisoning initiation voltage being not less than 4.6V, the poisoning agent initiates an electrochemical reaction system on the lithium secondary battery, releasing a primary poisoning element and an auxiliary poisoning element. At the positive electrode, the auxiliary poisoning element forms several auxiliary oxide layer regions on the surface of the positive electrode active material. The primary poisoning element diffuses through these auxiliary oxide layers, filling the lithium-deficient vacancies in the positive electrode active material with chlorine, thereby occupying the lithium vacancies in the lithium-deficient positive electrode active material and stabilizing the oxygen composition. This transforms the lithium-deficient, unstable positive electrode active material into a stable and disabled state. At the negative electrode, the poisoning agent transforms the highly active lithium component of the negative electrode active material into a stable lithium chloride state, effectively suppressing thermal runaway of the lithium secondary battery.

[0007] To achieve the above objectives, this invention proposes a lithium secondary battery poisoning system, comprising a lithium secondary battery and a poisoning agent. The lithium secondary battery has an electrochemical reaction system, which includes a positive electrode active material layer and a negative electrode active material layer opposite to the positive electrode active material layer. The positive electrode active material layer is a layered oxide. The poisoning agent is disposed inside or outside the electrochemical reaction system. When the lithium secondary battery reaches its own temperature at the poisoning initiation temperature or its voltage at the poisoning initiation voltage, the poisoning agent releases a primary poisoning element and an auxiliary poisoning element, wherein the poisoning initiation... The initial temperature is in the range of 120°C to 200°C, the poisoning initiation voltage is not less than 4.6V, the auxiliary poisoning element forms several auxiliary oxide layers on the surface of the positive electrode active material layer, and then the main poisoning element diffuses through these auxiliary oxide layers and occupies the lithium extraction vacancies of the positive electrode active material layer to stabilize the positive electrode active material layer. The main poisoning element forms a stable compound with the lithium element of the negative electrode active material layer to stabilize the negative electrode. The main poisoning element is chlorine, and the auxiliary poisoning element is boron, aluminum, germanium, titanium or a mixture of at least two of the above materials.

[0008] The following detailed description through specific embodiments will make it easier to understand the purpose, technical content, features and effects achieved by the present invention. Attached Figure Description

[0009] Figure 1 is a schematic diagram of an embodiment of the electrochemical reaction system of the present invention, in which the poisoning agent is disposed in a lithium secondary battery.

[0010] Figure 2 is a schematic diagram of another embodiment of the electrochemical reaction system of the present invention in which the poisoning agent is disposed in a lithium secondary battery.

[0011] Figure 3 is a schematic diagram of another embodiment of the electrochemical reaction system of the present invention in which the poisoning agent is disposed in a lithium secondary battery.

[0012] Figure 4 is a schematic diagram of an embodiment of the present invention in which the poisoning agent is coated with a protective layer.

[0013] Figure 5 is a schematic diagram of an embodiment in which the poisoning agent of the present invention is disposed outside the electrochemical reaction system of a lithium secondary battery.

[0014] Figure 6 is an experimental graph showing the activation of the poisoning agent of the present invention by voltage triggering.

[0015] Figure 7 is a graph showing the performance of a lithium secondary battery with the poisoning agent of the present invention in suppressing thermal runaway of a lithium secondary battery.

[0016] Figure 8 is a schematic diagram showing that, after the poisoning reaction begins in this invention, a coating layer is formed on the surface of the positive electrode active material, consisting of several auxiliary oxide layers and an unbroken CEI layer.

[0017] Figure 9 is a schematic diagram of the formation of an interface modification layer on the surface of an oxidized solid electrolyte (particle) according to the present invention. Detailed Implementation

[0018] To make the advantages, spirit, and features of the present invention more readily apparent, detailed descriptions and discussions will follow with reference to embodiments. It should be noted that these embodiments are merely representative examples of the present invention and are not intended to limit the implementation methods and scope of protection of the present invention to these embodiments. The purpose of providing these embodiments is solely to make the disclosure of the present invention more thorough and easily understood.

[0019] The terminology used in the various embodiments disclosed in this invention is for the purpose of describing particular embodiments only and is not intended to limit the various embodiments disclosed in this invention. Unless explicitly indicated otherwise, the singular forms used also include the plural forms. Unless otherwise specified, all terms used in this specification (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which the various embodiments disclosed in this invention pertain. The foregoing terms (such as those defined in general-purpose dictionaries) are to be interpreted as having the same meaning as in the context of the same technical field and are not to be interpreted as having an idealized or overly formal meaning unless explicitly defined in the various embodiments disclosed in this invention.

[0020] In the description of this specification, references to terms such as "an embodiment," "a specific embodiment," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment is included in at least one embodiment of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments.

[0021] In this specification, the word “about” is used to describe and indicate small variations. For example, when used in conjunction with numerical values, the word may refer to a range of variation less than or equal to ±10% of the stated value, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%.

[0022] This invention relates to a lithium secondary battery poisoning system and a disabled lithium secondary battery. The poisoning system is used to suppress thermal runaway of the lithium secondary battery. The poisoning system consists of a poisoning agent that can be placed inside or outside the electrochemical reaction system of the lithium secondary battery. The poisoning agent poisons the electrochemical reaction system in conjunction with the temperature of the lithium secondary battery itself to achieve so-called self-poisoning. Alternatively, the poisoning agent can be triggered to release poisoning components when the voltage of the lithium secondary battery reaches a poisoning initiation voltage to perform so-called self-poisoning of the lithium secondary battery.

[0023] The electrochemical reaction system includes a positive electrode active material layer; a negative electrode active material layer opposite to the positive electrode active material layer; and a first electrolyte for transporting lithium ions between the positive and negative electrode active material layers. This first electrolyte is the main electrolyte of the lithium secondary battery. The definition of the main electrolyte is that, when there are at least two electrolytes in the lithium secondary battery, the first electrolyte has the largest volume proportion in the area where the electrolyte can be placed. The first electrolyte can be selected from various forms of electrolytes in the prior art based on the position of the poison relative to the electrochemical reaction system. Examples include pure organic liquid electrolytes, pure colloidal electrolytes, pure condensed electrolytes, or pure solid electrolytes, or a mixture of at least two of the above. For example, the first electrolyte may be primarily a pure liquid, pure colloidal, or pure condensed electrolyte, supplemented by an arbitrary proportion of an oxide solid electrolyte (which is a type of pure solid electrolyte), or vice versa. Alternatively, it can be primarily an oxide solid electrolyte, supplemented by a pure organic liquid electrolyte, pure colloidal electrolyte, pure condensed electrolyte, or solid polymer electrolyte. The positive electrode active material layer of a lithium-ion secondary battery using this poisoning agent can be composed of several positive electrode active material particles, conductive materials, and binders. These positive electrode active material particles are layered lithium oxides containing elements nickel and manganese, elements nickel and aluminum, or simultaneously containing elements nickel, manganese, and aluminum. More preferably, they also contain elements cobalt to form so-called ternary positive electrode active materials such as NMC and NCA, or quaternary positive electrode active materials such as NCMA. For example, the positive electrode active material particles are selected from LiNi. 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (abbreviated as 111), LiNi 0.4 Co 0.2 Mn 0.4 O2 (abbreviated as 424), LiNi 0.5 Co 0.2 Mn 0.3 O2 (abbreviated as 523), LiNi 0.6 Co 0.2 Mn 0.2 O2 (abbreviated as 622), LiNi 0.8 Co 0.1 Mn 0.1 O2 (abbreviated as 811) or LiNi 0.9 Co 0.05 Mn 0.05 O2 (abbreviated as 955), LiNi 0.8 Co 0.15 Al 0.05 O2, LiNi 0.84 Co 0.12 Al 0.04 O2, LiNi 0.88 Co 0.06Mn 0.03 Al 0.03 O2 or LiNi 0.9 Co 0.04 Mn 0.03 Al 0.03 O2, etc. The negative electrode active material can be selected from lithium metal or materials that can be alloyed with lithium, such as silicon, tin, indium, or their oxide forms, such as silicon oxide. Therefore, the negative electrode active material layer is a film or sheet of lithium metal, or it is a mixture of lithium alloyable material particles, binder, and conductive material coated together.

[0024] At the onset of poisoning, a portion of the CEI (Cathode Electrolyte Interface) layer on the surface of the positive electrode active material 30 is in a collapsed state, thus exposing part of the surface of the positive electrode active material 30. At the poisoning initiation temperature, the poisoning agent releases a primary poisoning element and an auxiliary poisoning element into the electrochemical reaction system of the lithium secondary battery. The active sites of -OH, -O-, or functional groups exposed on the surface of the positive electrode active material will form an auxiliary oxide layer 34 (also called an auxiliary passivation layer) with the auxiliary poisoning element. Therefore, the coating layer 36 on the surface of the positive electrode active material is composed of the uncollapsed CEI layer 32 (formed by the reaction between the surface of the positive electrode active material and the electrolyte) and several auxiliary oxide layers 34 arranged in a disordered manner, as shown in Figure 8. Although the positive electrode active material is shown as a circle in this figure, this does not limit the active material used in this application to only be spherical; it can also be polygonal particles. Most positive electrode active materials have active sites with -OH, -O-, or functional groups on their surface. By having an auxiliary poisoning element react with these active sites to form an oxide, premature reaction with the main poisoning element of the poisoning agent can be avoided. The auxiliary oxide layer 34 is a non-dense passivation layer compared to the CEI layer 32, thus providing pores (or pathways) for the main poisoning element to pass through this auxiliary oxide layer 34 and diffuse to the lithium-deficient vacancies on the surface of the positive electrode active material 30, reducing the barrier effect of the CEI layer on the surface of the positive electrode active material 30. When the lithium-deficient vacancies are occupied by the main poisoning element, the positive electrode active material no longer has vacancies for lithium atoms to fill. Therefore, the poisoned positive electrode active material loses the lithium-ion insertion and extraction capabilities that it should have as a positive electrode active material for lithium secondary batteries (i.e., it forms a disabled state). Furthermore, by occupying the lithium-deficient vacancies by the main poisoning element, the lattice distortion caused by lithium atom extraction in the positive electrode active material is resolved, thereby reducing or preventing oxygen release. The primary poisoning element is chlorine, which can also form stable bonds with other elements in the positive electrode active material, such as manganese or unreleased lithium. This auxiliary poisoning element can form the auxiliary oxide layer at active sites on the surface of the lithium-deficient positive electrode active material at a high temperature of not less than about 120°C. This auxiliary poisoning element can be selected from elements capable of forming compounds with the primary poisoning element (chlorine) to form a compound, and preferably, the compound is one that can exist in a gaseous state within a temperature range of room temperature to 200°C. For example, the compound that can release the primary poisoning element and the auxiliary poisoning element can be boron trichloride (BCl3), aluminum trichloride (AlCl3), germanium trichloride (GaCl3), titanium tetrachloride (TiCl4), or a mixture of at least two or more.The aluminum trichloride (AlCl3) and germanium trichloride (GaCl3) mentioned above are solids at room temperature, making them relatively easy to incorporate into the electrochemical reaction system of a lithium secondary battery.

[0025] In this invention, the method for determining whether the poisoning agent releases the main poisoning element and auxiliary poisoning element into the electrochemical reaction system of the lithium secondary battery can be based on the temperature feedback from the lithium secondary battery itself, or by controlling the voltage that the lithium secondary battery withstands. Therefore, when the temperature of the lithium secondary battery during normal charging and discharging is lower than the poisoning initiation temperature or the voltage is lower than the poisoning initiation voltage, the poisoning agent will essentially or substantially not release the main poisoning element and auxiliary poisoning element into the electrochemical reaction system of the lithium secondary battery. Therefore, the poisoning agent does not participate in the electrochemical reaction caused by lithium ion transfer in the lithium secondary battery, and thus will not affect the use of the lithium secondary battery.

[0026] When the poisoning agent of the present invention is disposed outside the electrochemical reaction system, since the main poisoning element and auxiliary poisoning element of the poisoning agent do not affect the operation of the lithium secondary battery, it is not necessary to use a protective layer such as a capsule to encapsulate the poisoning agent. "Disposing outside the electrochemical reaction system" here refers, for example, to being disposed at the free end of the current collector layer away from the active material layer, and the current collector layer has a perforation at the location of the poisoning agent that can be opened at the poisoning initiation temperature, allowing the poisoning agent to enter the electrochemical reaction system inside the lithium secondary battery. In this architecture, if the main electrolyte of the lithium secondary battery is a liquid electrolyte with cyclic carbonates, a large amount of the poisoning agent will be consumed in the reaction with this liquid electrolyte, thus affecting the poisoning efficiency of the positive and negative electrode active materials. Therefore, when the poisoning agent is disposed outside the electrochemical reaction system, it is preferable to use an oxide solid electrolyte, sulfide solid electrolyte, pure colloidal electrolyte, or halide solid electrolyte, which does not react extensively with the poisoning agent, as the electrolyte body of the lithium secondary battery. The optimal choice is to use oxide solid electrolytes and halide solid electrolytes as the main electrolytes, which do not react with poisoning agents at all. Among them, halide solid electrolytes with high stability are preferred. Examples include Li3InCl6, LiYCl6, LiZrCl6, Li3ErCl6, Li3ScCl6, Li2TiCl6, LiHfCl6, Li3YBr6, Li3ErBr6, Li3ScCl6, Li3HoBr6, and Li3YCl. 6-x Br x ,Li3InCl 6-x Br x Li 2.85 Al 0.05 In 0.1 Cl6 or Li3Al 1-x Mx Cl6 (M = Y, In), LiAlCl4, Li2AlCl6, LiGaCl4, Li2GaCl6, etc.

[0027] However, when the poisoning agent is placed within an electrochemical reaction system, to prevent premature poisoning of the active materials in the positive or negative electrode active material layers or reaction with the organic electrolyte, a polymer protective shell is required to encapsulate the poisoning agent, forming a core-shell structure. Examples of suitable materials include paraffin oil, microcrystalline wax, polyethylene wax, low-density polyethylene (PE), poly(trans-1,4-butadiene), poly(tetramethylene oxide), isotactic poly(methyl methacrylate), poly(ethylene oxide), polyethylene adipate, and isotactic poly(1-butene). Thermosensitive decomposition materials such as 1-butene and polyethylene (PE) completely seal the surface to prevent contact with organic electrolytes containing cyclic carbonates, thereby avoiding reaction or ring-opening polymerization, which would cause the lithium secondary battery to lose its electrochemical reactivity prematurely. Furthermore, when the main electrolyte is a pure liquid organic electrolyte, such as one containing cyclic carbonates, the CH3-O bonding structure can be adjusted to a CF3-O bonding structure. The high electronegativity of CF3 reduces or eliminates the chance of bond breaking catalyzed by poisoning agents. Such material adjustments can also be used as the main electrolyte in this invention.

[0028] When the poisoning agent exists in a protective shell and is mixed into the positive or negative electrode active material, the primary electrolyte can be any type of electrolyte, such as a pure organic liquid electrolyte, a pure colloidal electrolyte, a pure condensed electrolyte, or a pure solid electrolyte, or a mixture of at least two of the above. For example, the primary electrolyte may be mainly a pure liquid, pure colloidal, or pure condensed electrolyte, and may be mixed with an arbitrary proportion of an oxide solid electrolyte (which is a type of pure solid electrolyte) as an auxiliary or secondary component. Conversely, it may also be mainly an oxide solid electrolyte, with pure organic liquid electrolyte, pure colloidal electrolyte, pure condensed electrolyte, or solid polymer electrolyte as an auxiliary component.

[0029] When the poisoning agent exists in a protective shell and is mixed into the inorganic powder of the separator, the primary electrolyte should avoid organic liquid electrolytes, as these will result in poor poisoning of the active materials at the positive and negative terminals of the lithium secondary battery, for reasons previously stated and will not be repeated. Preferably, the primary electrolyte of the lithium secondary battery is an oxide solid electrolyte, sulfide solid electrolyte, pure colloidal electrolyte, or halide solid electrolyte that does not react significantly with the poisoning agent. Most preferably, the primary electrolyte is an oxide solid electrolyte or a halide solid electrolyte that does not react with the poisoning agent at all, with halide solid electrolytes being particularly preferred due to their high stability. When the primary electrolyte is a solid electrolyte, a solid electrolyte system dominated by an oxide solid electrolyte is even more preferred. Furthermore, the primary electrolyte can also be a composite solid electrolyte, such as an oxide solid electrolyte as the main component and a solid polymer electrolyte as an auxiliary component. The terms "primary" and "auxiliary" here refer to the volume ratio in the composite solid electrolyte, with the proportion of the primary component being higher than that of the auxiliary component.

[0030] To reduce the reactivity of poisoning agents (such as AlCl3 or GaCl3) with polymeric components within lithium-ion batteries, such as reducing the reactivity of poisoning agents with polymers used as shells or solid polymer electrolytes, a low-temperature molten salt formation method can be employed. This can be achieved by adding potassium chloride (KCl), zinc chloride (ZnCl4), lithium chloride (LiCl), sodium chloride (NaCl), magnesium chloride (MgCl2), ferric chloride (FeCl2), or ferric chloride (FeCl3) to AlCl3 and / or GaCl3 to form a low-temperature molten salt, such as LiAlCl4, NaAlCl4, or Li... x1 Na y1AlCl4, where x1 > 0, y1 > 0, and other molten salt combinations. For example, a composite salt layer can be formed by eutectic mixing of AlCl3:NaCl:KCl in a ratio of 61:26:13. Alternatively, it can be a eutectic mixture of AlCl3:NaCl:KCl in a ratio of 59:29:12, 75:16:9, or 76:11:5:8. This method can enhance the stability of the core-shell structure. In other words, the poisoning agent contained inside the polymer shell is a low-temperature molten salt that exhibits low reactivity to the polymer shell. Of course, in addition to stability, such a combination of low-temperature molten salts can also achieve the release of AlCl3 and / or GaCl3 within an appropriate high-temperature range through the selection of other components, such as the shell material. The sublimation temperature must be between 150 and 200 degrees Celsius; otherwise, the significance of stabilizing and controlling the positive and negative electrode active materials before thermal runaway of the lithium secondary battery is lost.

[0031] Furthermore, the poisoning agent prepared by low-temperature molten salt method can also be directly mixed with positive or negative electrode active materials without the need to form a core-shell structure.

[0032] In examples with a core-shell structure, organic salts can be added to accelerate the melting of the composite salt layer. Examples of such salts include tetrabutylammonium chloride (mp (melting point) = 70℃), 1-butyl-3-methylimidazolium chloride (mp = 41℃), 1-ethyl-3-methylimidazolium chloride (mp = 84℃), tetrabutylammonium bromide (mp = 103℃), tetraheptylammonium bromide (mp = 89℃), and tributylhexadecylphosphonium bromide (mp = 61℃). Furthermore, the poisoning agent may also contain a reinforcing agent or a special ligand, which can accelerate the decomposition of compounds (metal chlorides) containing the main poisoning element and auxiliary poisoning elements, provide an oxidizing or catalytic environment, accelerate the generation of chloride ions, and reduce the occurrence of interfacial side reactions, allowing more chloride ions to diffuse into the interior of the positive electrode active material. This reinforcing agent can be sulfur dioxide (SO2), especially since SO2, under low temperature or high pressure, can dissolve aluminum trichloride (AlCl3) or germanium trichloride (GaCl3), thus converting the solid AlCl3 and / or GaCl3 and the gaseous SO2 within the shell into a liquid state of AlCl3·X2SO2 or GaCl3·X3SO2, where X2 > 0 and X3 > 0. However, the presence of SO2 will cause a dense sulfate layer to form on the surface of the positive electrode active material, hindering the diffusion of chloride ions (Cl... - The boron can enter the lattice of the positive electrode active material. Therefore, a boron-containing compound can be applied to the surface of the positive electrode active material, or boron trioxide (B2O3) or lithium bis(oxalatoborate) (LiBOB) can be added to the first electrolyte to form a borate layer that has a lower resistance to the movement of chloride ions.

[0033] Furthermore, LiAlCl4, Li2AlCl6, LiGaCl4, and Li2GaCl6 are also halide solid electrolytes, and they possess the ability to release AlCl3 and GaCl3. Simultaneously, SO2, under low temperature or high pressure, can dissolve these halide solid electrolytes, forming a fluidized, non-Newtonian fluid-based all-inorganic electrolyte with SO2 as the solvent. Due to the presence of SO2, this fluidized all-inorganic electrolyte causes LiAlCl4 or LiGaCl4 to decompose into LiCl and AlCl3 or GaCl3 at even lower temperatures. AlCl3 and GaCl3 release AlCl3 and / or GaCl3 at approximately 120°C to 150°C. Simultaneously, the presence of SO2 makes AlCl3 / GaCl3 more prone to sublimation into gas, reacting with the positive and / or negative electrode active materials. Therefore, this lithium secondary battery can directly use this fluidized inorganic electrolyte as the main electrolyte, while also acting as a poisoning agent. Alternatively, the fluidized inorganic electrolyte can also be used as an auxiliary electrolyte, i.e., the second electrolyte in the lithium secondary battery electrolyte system. However, in this case, the poisoning agent and / or SO2 will inevitably cause depolymerization of the cyclic carbonate organic electrolyte. Therefore, it is preferable for the first electrolyte to be a solid electrolyte system or a halide solid electrolyte that does not dissolve in SO2, especially a system dominated by oxide solid electrolytes. For example, a composite solid electrolyte, such as an oxide solid electrolyte as the main component and a solid polymer electrolyte as the auxiliary component. This applies to both solid AlCl3 and GaCl3, and liquid AlCl3·X2SO2 or GaCl3·X3SO2, where X2>0 and X3>0. The halide solid electrolyte can be selected from Li3InCl6, LiYCl6, LiZrCl6, Li3ErCl6, Li3ScCl6, Li2TiCl6, LiHfCl6, or Li3ScCl6, etc.

[0034] Furthermore, eutectic salts formed by adding AlCl3 and / or GaCl3 to LiCl, or the coexistence of both salts such as LiCl + AlCl3 or LiCl + GaCl3, can be dissolved by SO2 to form a non-Newtonian fluid inorganic electrolyte. For example, LiAlCl4·X4SO2 or LiGaCl4·X5SO2, where X4 > 0 and X5 > 0, preferably X4 > 1 and X5 > 1. At around 150°C, SO2 evaporates into gas in this non-Newtonian fluid inorganic electrolyte, while the eutectic salts LiAlCl4 or LiGaCl4 decompose into LiCl and AlCl3 or GaCl3. AlCl3 and GaCl3 sublimate into gas at 150°C to 200°C, reacting with the positive electrode active material. LiAlCl4·X4SO2 is a preferred formulation, and 1.5 ≤ X4 ≤ 3.0 is a preferred example. Therefore, the poisoning agent under these conditions can also be used as a second electrolyte in the lithium secondary battery of the present invention, and the second electrolyte is used as a poisoning agent at a high temperature of 150°C.

[0035] The eutectic salts formed by adding LiCl to AlCl3 and / or GaCl3, or the eutectic salts formed by the presence of two salts (LiCl+AlCl3 or LiCl+GaCl3), can also be used as a completely inorganic halide solid electrolyte, such as LiAlCl4, LiAl2Cl6, LiGaCl4 or LiGa2Cl6, or a mixture of at least two of the above salts in different proportions. However, because the ionic conductivity of this halide solid electrolyte composed of Li, Cl and Al or Ga (hereinafter referred to as LiCl-Al / Ge halide solid electrolyte) is relatively low, it can be used as a second electrolyte (auxiliary electrolyte). The main electrolyte is an oxide solid electrolyte, sulfide solid electrolyte, pure colloidal electrolyte, or non-LiCl-Al / Ge halide solid electrolyte, which has a higher ionic conductivity than LiCl-Al / Ge halide solid electrolyte and does not react more with poisoning agents, and serves as the electrolyte body (first electrolyte) of this lithium secondary battery. When this LiCl-Al / Ge halide solid electrolyte is used as the auxiliary electrolyte (second electrolyte) for lithium-ion transfer in the lithium secondary battery, it acts as both a solid electrolyte and a poisoning agent supplier. It can fully contact both the positive and negative electrode active materials, and at approximately 150–190 degrees Celsius, it releases AlCl3 and / or GaCl3 poisoning agent gases, effectively fulfilling both roles. When this LiCl-Al / Ge halide solid electrolyte is incorporated into either the positive or negative electrode active material layer, the primary electrolyte can be an organic liquid electrolyte.

[0036] Alternatively, the oxide solid electrolyte can be modified with LiAlCl4, Li2AlCl6, LiGaCl4, or Li2GaCl5. Since these LiCl-Al / Ge halide solid electrolytes, like polymer electrolytes and sulfide electrolytes, are deformable, they can be applied to the surface of the oxide solid electrolyte (particles) to form an interface modification layer, as shown in Figure 9. An interface modification layer 44 is provided on the surface of the oxide solid electrolyte (particles) 42. This method not only improves the interface resistance between adjacent solid electrolytes (particles) 42, but also allows direct contact with the positive and negative electrode active materials, enabling direct poisoning of the active materials under appropriate conditions. Although the ion conductivity of these LiCl-Al / Ge halide solid electrolytes is poor, the impact on ion conduction can be reduced by decreasing the thickness of the interface modification layer.

[0037] The poisoning agent of this invention mainly reacts with the positive and negative electrode active materials in a gaseous state, but it can also react in a solid or liquid state. For example, if the original positive electrode active material is in the form of Li... x6 (Ni a1 Co b1 Mn c1 O z1 When represented by ), the positive electrode active material poisoned by the poisoning agent of the present invention will become a deactivated positive electrode active material rich in the main poisoning element, and its chemical formula is Li. x7 Cl y2 (Ni a2 Co b2 Mn c2 O z2 ), where x6>x7, a1≥0, b1≥0, c1≥0, z1≥0, and even x7<y2, a2≥0, b2≥0, c2≥0, z2≥0.

[0038] Under lithium-deficient conditions, the main poisoning element, chloride ions or chlorine atoms, reacts with lithium-deficient cathode active materials in the following ways: 1. Lithium substitution: Chloride ions can enter the original lithium ion positions in the NCM structure and form lithium chloride with the remaining lithium; 2. Enhanced stability: Chlorine has a high electronegativity of approximately 3.16, which makes its interaction with transition metals (such as nickel, cobalt, and manganese) and oxygen very strong, enabling the formation of stable chemical bonds. Therefore, the introduction of chlorine can stabilize the material structure, reduce oxygen release and material decomposition, thereby improving thermal stability and cycle stability.

[0039] In practice, the poisoning agent material particles in this case can have an average particle size of 0.1 micrometers (μm) to 150 micrometers (μm). When the poisoning agent with the protective layer is mixed between positive electrode active material particles or negative electrode active material particles, in order to avoid the agglomeration effect caused by excessively small particle size during the mixing process, the particle size of the poisoning agent is about one-third of the positive electrode active material layer or the negative electrode active material layer. For example, the average particle size of the poisoning agent particles is 0.1 micrometers to 100 micrometers, preferably 0.1 micrometers to 10 micrometers.

[0040] In this case, the negative electrode active material can be selected from lithium metal or materials that can alloy with lithium, such as silicon, tin, indium, or their oxide forms, such as silicon oxide. Since the negative electrode active material itself is lithium metal or is in a lithium-rich state due to the charging and discharging process of a lithium secondary battery, chlorine will react with lithium to form a relatively stable and dense lithium chloride layer, serving as a protective layer to suppress thermal runaway. Furthermore, the presence of solid AlCl3 and / or GaCl3, gaseous SO2, or SO2 liquid containing dissolved AlCl3 and / or GaCl3, will further dissolve the lithium chloride layer, allowing chloride ions to continuously react into the lithium-rich region inside the negative electrode active material to form stable LiCl, thus stabilizing the negative electrode.

[0041] The following will describe various implementation methods based on the above description.

[0042] The poisoning agent of this invention can be applied to various types of lithium secondary batteries, such as cylindrical batteries, angular batteries, and pouch batteries. When the poisoning agent of this invention is placed in the electrochemical reaction system of the lithium secondary battery shown in Figure 1, the lithium secondary battery (also referred to as a single cell) 10 includes a positive electrode current collector layer 12; a positive electrode active material layer 13 located on the inner surface 121b of the positive electrode current collector layer 12; a negative electrode current collector layer 14; a negative electrode active material layer 15 located on the inner surface 141b of the negative electrode current collector layer 14 and corresponding to the positive electrode active material layer 13; a separator layer 16 located between the positive electrode active material layer 13 and the negative electrode active material layer 15; and a polymer frame 18, one end of which is bonded to the remaining inner surface of the positive electrode current collector layer 12 (not covered by the positive electrode active material layer 13). The positive electrode current collector layer 12, the frame 18, and the negative electrode current collector layer 14 form a closed space 19 to accommodate the positive electrode active material layer 13, the separator layer 16, the negative electrode active material layer 15, and the electrolyte system. The positive electrode current collector layer 12, the frame 18, and the negative electrode current collector layer 14 serve as encapsulation components for the lithium secondary battery 10, preventing external environmental influences such as moisture on the positive electrode active material layer 13, the separator layer 16, and the negative electrode active material layer 15. The electrolyte system of the lithium secondary battery is housed within the closed space 19. Furthermore, when any electrolyte in the electrolyte system is a solid electrolyte or a composite solid electrolyte, the electrolyte can also be used directly as a separator layer.

[0043] The poisoning agent 17 of the present invention can be disposed on the surface of the positive electrode active material layer 13 (i.e., the positive end), adjacent to the isolation layer 16, as shown in FIG1; or, the poisoning agent 17 can be disposed in the isolation layer 16 used to prevent electrical contact between the positive electrode active material layer 13 and the negative electrode active material layer 15, i.e., mixed with the inorganic powder of the isolation layer 16, as shown in FIG2; or, the poisoning agent 17 can be mixed together with the positive electrode active material (particles) 131 of the positive electrode active material layer to form an additive within the positive electrode active material layer 13, i.e., the poisoning agent 17 is located between the positive electrode active material (particles) 131, as shown in FIG3. The same applies to the negative end portion, so it will not be described in detail.

[0044] In the above embodiments, as previously described, the outer surface of the poisoning agent 17 may have a protective layer 171, as shown in FIG4, to seal the poisoning agent 17 to prevent the components of the poisoning agent 17 from interacting with the first electrolyte or electrolyte system, and to control the timing of the release of the poisoning agent 17 by the presence of the protective layer 171.

[0045] Furthermore, when the first electrolyte system is an oxide solid electrolyte, the possibility of the poison reacting with the cyclic carbonate organic electrolyte can be eliminated. Therefore, the poison can be directly mixed with the oxide solid electrolyte and the composite solid electrolyte. Thus, whether at the positive electrode, negative electrode, or separator, since the poison will not react with the oxide solid electrolyte, the same effect can be achieved even without core-shell protection. The detailed description of the material selection for the electrolyte system in this lithium secondary battery is as previously stated and will not be repeated here.

[0046] When the poisoning agent is placed outside the electrochemical reaction system of the lithium secondary battery, at least one perforation can be provided on the encapsulation component used to encapsulate the electrochemical reaction system to form a pathway that allows communication from the external environment of the lithium secondary battery to the electrochemical reaction system of the lithium secondary battery. The perforation can be pre-formed and remain closed until a set temperature (e.g., 150°C) or a certain pressure is reached, or the perforation can be formed by some means or reaction, such as by the pressure caused by the gas generated by the electrochemical system during the high-temperature process or by the etchability of the gas, which increases the pressure on the hermetic encapsulation component of the lithium secondary battery, such as the casing, or by the pressure increase caused by additional gas-generating components or by the etchability of the gas, which damages the casing to create the perforation. For example, as shown in Figure 5, the poisoning agent 17 of the present invention is disposed on the outer surface of a positive electrode current collector layer 12. The positive electrode current collector layer 12 has several perforations 122 that penetrate the positive electrode current collector layer 12 and are connected to the electrochemical reaction system of the lithium secondary battery 10. The perforations 122 are filled with a filler 22 (e.g., silicone polymer (also known as silica gel)) that melts near the poisoning initiation temperature or depolymerizes due to AlCl3. When the temperature of the lithium secondary battery 10 reaches or approaches the poisoning initiation temperature, the filler 22 melts and exposes the perforations 122, allowing the poisoning agent 17 to enter the electrochemical reaction system of the lithium secondary battery 10 and react with the positive electrode active material layer 13 adjacent to the positive electrode current collector layer 12, causing the positive electrode active material layer 13 to lose its function and achieve safety. The same applies to the negative electrode portion, so it will not be described in detail. Furthermore, the outer surface of the poisoning agent 17 may be partially covered with a covering layer 24 to prevent substances in the external environment, such as moisture, from damaging or affecting the poisoning agent 17, and to prevent the poisoning agent 17 from evaporating. Additionally, when the filler 22 melts, the covering layer 24 can also act as a sealing member for the perforation 122, preventing oxygen from entering the lithium secondary battery 10 through the perforation 122. Moreover, the lithium secondary battery 10 can be housed within an aluminum bag, forming a so-called pouch battery. The poisoning agent 17 can also be disposed between the lithium secondary battery and the aluminum bag. A detailed description of the material selection for the electrolyte system in this type of lithium secondary battery, as previously described, will not be repeated here.

[0047] In this invention, the isolation layer 16 can be a substrate-free or substrate-based form formed by stacking inorganic particles with an adhesive. The substrate is a thin film or sheet-like object formed from polymer materials or inorganic fibers, which may or may not have pores. The inorganic particles can be ion-transferring, i.e., solid electrolytes, or non-ion-transferring, such as alumina, silicon dioxide, or titanium dioxide, or nitrides, such as silicon nitride (Si3N4), etc.; or the inorganic particles can be salt particles, such as sulfates, phosphates, or halide salts, or a mixture of at least two different types or materials. When the inorganic particles are selected from alumina, their crystalline phase can be selected from α, β, γ phases, or a mixture of two or more of the above to form multiple crystalline phases or polymorphs, with the α phase being preferred, or the isolation layer being formed with a higher proportion of the α phase. Materials for lithium-ion-transferring solid electrolytes can include oxides such as LATP, LAGP, LLZO, or LASO (LiAlSiO4). Furthermore, since the poisoning agent in this case begins to activate and release before the critical temperature of the lithium secondary battery's severe temperature rise, the insulating layer is preferably designed to remain intact or without electronic insulation at 150°C to 200°C. This prevents safety issues arising from contact between the positive and negative electrode active materials before they reach a stable state (or are poisoned and lose their electrochemical reactivity).

[0048] The poisoning agent used in this case can also be activated by voltage, thereby attacking the positive and negative electrode active materials. This is especially true when the poisoning agent is a LiCl-Al / Ge halide solid electrolyte such as LiAlCl4, LiAlCl6, LiGaCl4, or Li2GaCl6, or in embodiments where SO2 is used to coordinate it to form a fluid electrolyte. In these cases, voltage-driven poisoning reactions are possible. For example, these LiCl-Al / Ge halide solid electrolytes are disposed within the positive electrode and exist as a second electrolyte (either a solid electrolyte or a fluidized solid electrolyte) in the electrochemical reaction system of a lithium secondary battery, or are formed on the interface modification layer 44 of the oxide solid electrolyte (particles) 42, as shown in Figure 9. Because these LiCl-Al / Ge halide solid electrolytes are unstable at high voltages (not less than 4.6V), they decompose to release AlCl3 and / or GaCl3. Simultaneously, at high voltages, the CEI layer on the surface of the active material also partially decomposes, resulting in a reaction process similar to temperature-driven poisoning. Please refer to Figure 6, which demonstrates that the poisoning agent is activated when subjected to a voltage of not less than 4.6 volts, and that the poisoning agent does not cause a drastic temperature rise in the lithium secondary battery when activated by a high voltage. This voltage of not less than 4.6 volts is referred to in this case as a poisoning initiation voltage. Preferably, the poisoning initiation voltage is greater than 4.6 volts.

[0049] Please refer to Figure 7, which shows the state of a lithium-ion secondary battery (labeled as "sample" in the figure) with a ceramic separator and the poisoning agent of this invention, and a commercially available lithium-ion secondary battery (using a Panasonic-NCR21007A in this experiment) undergoing thermal runaway testing using the Heat-wait-Seek method with an Accelerated Runaway Analysis Calorimeter (ARC). The positive electrode active material used in the lithium-ion secondary battery of this invention is NMC955, and the negative electrode active material is silicon. As shown in the figure, the poisoning agent of this invention begins to inhibit the thermal runaway reaction at approximately 120°C, and then continues to inhibit the reaction until the lithium-ion secondary battery is completely poisoned and inoperable. In contrast, a commercially available lithium-ion secondary battery without a thermal runaway inhibitor and using a liquid electrolyte will exhibit thermal runaway under the same testing method.

[0050] In summary, this invention provides a lithium secondary battery poisoning system and a deactivated lithium secondary battery. When the lithium secondary battery is heated to the poisoning initiation temperature, a poisoning agent placed inside or outside the electrochemical reaction system of the lithium secondary battery releases the main poisoning element and auxiliary poisoning element into the electrochemical reaction system of the lithium secondary battery. The auxiliary poisoning element forms a non-dense oxide layer on the surface of the lithium-deficient positive electrode active material particles, allowing the main poisoning element to diffuse into the interior of the positive electrode active material particles and occupy the lithium-deficient vacancies in the lithium-deficient positive electrode active material, thereby deactivating the lithium-deficient positive electrode active material, forming a lower energy state, reducing the voltage of the entire battery, and simultaneously cutting off the electrochemical reaction pathway. At the negative electrode, low-activity lithium chloride is formed with highly active lithium metal, thereby effectively terminating the thermal runaway of the lithium secondary battery. Alternatively, when the poisoning agent is a halide solid electrolyte containing aluminum chloride or germanium chloride and serves as the second electrolyte in the system, the thermal runaway of the lithium secondary battery can be terminated by increasing the voltage of the lithium secondary battery to not less than 4.6 volts, causing the halide solid electrolyte to release the main poisoning element and auxiliary poisoning element. Compared to existing thermal runaway suppression methods, this invention mainly suppresses thermal runaway directly from the point of maximum energy release during thermal runaway and the main body driven by the entire electrochemical reaction, namely the active material. Furthermore, it utilizes the temperature or voltage of the lithium secondary battery as a trigger mechanism for the poisoning action, thus more effectively improving the safety of the lithium secondary battery.

[0051] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the invention. All equivalent variations or modifications made in accordance with the features and spirit described in the claims of this invention should be included within the scope of the claims.

[0052] Figure Label Explanation: 10 Lithium secondary battery; 12 Positive electrode current collector layer; 121a Outer perimeter; 121b Inner surface portion; 13 Positive electrode active material; 14 Negative electrode current collector layer; 141a Outer perimeter; 141b Inner surface portion; 15 Negative electrode active material; 16 Separator layer; 17 Poisoning agent; 171 Protective layer; 18 Polymer frame; 19 Enclosed space; 22 Filler; 24 Covering layer; 122 Perforation; 131 Positive electrode active material particles; 30 Positive electrode active material; 32 Unbroken SEI layer; 34 Auxiliary oxide layer; 36 Coating layer; 42 Oxidized solid electrolyte (particles); 44 Interface modification layer.

Claims

1. A lithium secondary battery poisoning system, comprising: A lithium secondary battery having an electrochemical reaction system comprising: A positive electrode active material layer comprising several positive electrode active material particles, wherein the positive electrode active material particles are made of layered lithium oxide; and A negative electrode active material layer, which is opposite to the positive electrode active material layer; and A poisoning agent is disposed within or outside the electrochemical reaction system. The poisoning agent releases a primary poisoning element and an auxiliary poisoning element at a poisoning initiation temperature or a poisoning initiation voltage. The poisoning initiation temperature is in the range of 120°C to 200°C, the poisoning initiation voltage is not less than 4.6V, the primary poisoning element is chlorine, and the auxiliary poisoning element is boron, aluminum, germanium, titanium, or a mixture of at least two of the above materials. in, The auxiliary poisoning element forms several auxiliary oxide layers on the surface of the positive electrode active material particles. The main poisoning element diffuses into the interior of the positive electrode active material particles through the auxiliary oxide layers, occupying lithium extraction vacancies. The main poisoning element and the lithium in the negative electrode active material layer form stable lithium chloride.

2. The lithium secondary battery poisoning system according to claim 1, wherein when the poisoning agent is disposed outside the electrochemical reaction system, the electrochemical reaction system includes a first electrolyte, which is a primary electrolyte for transporting lithium ions between the positive electrode active material layer and the negative electrode active material layer, the first electrolyte being selected from pure colloidal electrolyte, pure condensed electrolyte, sulfide solid electrolyte, halide solid electrolyte or oxide solid electrolyte, or a mixture of at least two of the above.

3. The lithium secondary battery poisoning system according to claim 2, wherein the poisoning agent is AlCl3 and / or GaCl3.

4. The lithium secondary battery poisoning system according to claim 3, wherein the poisoning agent further comprises a eutectic, the material of which is lithium chloride, sodium chloride, magnesium chloride, potassium chloride, zinc chloride, ferric chloride, ferric chloride, or a mixture of at least two of the above materials.

5. The lithium secondary battery poisoning system according to claim 1, wherein when the poisoning agent is disposed in the electrochemical reaction system, the poisoning agent has a protective layer to form a core-shell structure, and the poisoning agent is disposed in the positive electrode active material layer or the negative electrode active material layer.

6. The lithium secondary battery poisoning system according to claim 5, wherein the electrochemical reaction system includes a first electrolyte, which is a primary electrolyte for transporting lithium ions between the positive electrode active material layer and the negative electrode active material layer, the first electrolyte being selected from organic liquid electrolyte, pure colloidal electrolyte, sulfide solid electrolyte, halide solid electrolyte or oxide solid electrolyte, or a mixture of at least two of the above.

7. The lithium secondary battery poisoning system according to claim 5, wherein the poisoning agent is AlCl3 and / or GaCl3.

8. The lithium secondary battery poisoning system according to claim 7, wherein the poisoning agent further comprises a eutectic, the material of which is lithium chloride, sodium chloride, magnesium chloride, potassium chloride, zinc chloride, ferric chloride, ferric chloride, or a mixture of at least two of the above materials.

9. The lithium secondary battery poisoning system according to claim 7, wherein the poisoning agent further comprises an enhancing agent, which is sulfur dioxide.

10. The lithium secondary battery poisoning system according to claim 1, wherein when the poisoning agent is disposed in the electrochemical reaction system, the poisoning agent further comprises a eutectic, the material of which is lithium chloride, sodium chloride, magnesium chloride, potassium chloride, zinc chloride, ferric chloride, ferric chloride, or a mixture of at least two of the above materials.

11. The lithium secondary battery poisoning system according to claim 10, wherein the electrochemical reaction system includes a first electrolyte, which is a primary electrolyte for transporting lithium ions between the positive electrode active material layer and the negative electrode active material layer, the first electrolyte being selected from pure colloidal electrolyte, sulfide solid electrolyte, halide solid electrolyte or oxide solid electrolyte, or a mixture of at least two of the above.

12. The lithium secondary battery poisoning system according to claim 11, wherein the poisoning agent is a second electrolyte of the lithium secondary battery, the volume ratio of the first electrolyte in the lithium secondary battery is greater than the volume ratio of the second electrolyte in the lithium secondary battery, and the second electrolyte is a halide solid electrolyte or a non-Newtonian fluid inorganic electrolyte.

13. The lithium secondary battery poisoning system according to claim 12, wherein when the poisoning agent is selected from LiAlCl4, Li2AlCl6, LiGaCl4 or Li2GaCl5, the first electrolyte is an oxide solid electrolyte, and the poisoning agent is disposed on the surface of the oxide solid electrolyte to form an interface modification layer.

14. The lithium secondary battery poisoning system according to claim 13, wherein the primary poisoning element and the auxiliary poisoning element are generated by the poisoning agent being triggered by the poisoning initiation voltage.

15. The lithium secondary battery poisoning system according to claim 1, wherein the lithium secondary battery further comprises an isolation layer disposed between the negative electrode active material layer and the positive electrode active material layer, the isolation layer being composed of stacked inorganic particles of lithium ion-transferable type, lithium ion-non-transferable type, or salt type, or a mixture of at least two different types or materials of the above-mentioned particles stacked together.

16. The lithium secondary battery poisoning system according to claim 1, wherein the lithium secondary battery further comprises: A positive current collector layer, located on the outer side of the positive active material layer away from the negative active material layer; and A negative electrode current collector layer is located on the outside of the negative electrode active material layer; When the poisoning agent is disposed outside the electrochemical reaction system, the poisoning agent is disposed outside the positive electrode current collector layer and / or outside the negative electrode current collector layer.

17. A deactivated lithium secondary battery poisoned by the poisoning system as described in claim 1, characterized in that... The surface of the positive electrode active material particles of the poisoned lithium secondary battery is covered with an auxiliary oxide layer, and some lithium positions within the positive electrode active material particles are occupied by chlorine. Lithium chloride is formed on the surface of the active material of the negative electrode active material layer.

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