Lithium secondary battery cell

Abstract

A lithium secondary battery cell, having a packaging component formed by a positive electrode current collector layer, a negative electrode current collector layer, and a plastic frame to enclose an electrochemical reaction system using a non-Newtonian fluid electrolyte formed from lithium tetrachloroaluminate as a salt and sulfur dioxide as a ligand, so as to minimize remaining space within the lithium secondary battery cell, thereby requiring volatilization of only a trace amount of the ligand to achieve a saturated vapor pressure, form a gas-liquid phase balance, and maintain normal operation of the lithium secondary battery cell; furthermore, at least any one of various material interfaces of the electrochemical reaction system has a ligand clamping region, which effectively resolves the issue of non-Newtonian fluid electrolytes generating electrolyte depletion regions. In addition, non-Newtonian fluid electrolytes will self-decompose at 120° C to 200° C to form chlorides and chloride ions, and passivate positive and negative active materials, thereby effectively resolving the problem of thermal runaway in lithium secondary battery cells.

Description

lithium secondary battery cells Technical Field

[0001] This invention relates to a lithium secondary battery cell, and more particularly to a lithium secondary battery cell having a non-Newtonian fluid electrolyte with sulfur dioxide as a coordinator and lithium tetrachloroaluminate as a salt. Background Technology

[0002] Lithium-ion batteries are widely used in various products, such as transportation vehicles, wearable products for consumer and industrial applications, portable devices and energy storage devices, etc., almost covering all aspects of people's daily lives. However, accidents involving lithium-ion batteries are frequently reported, such as fires and explosions of mobile phone batteries and electric vehicles. These are because there is still a lack of comprehensive and effective solutions to the safety issues of lithium batteries.

[0003] The primary factor causing fires and explosions in lithium-ion batteries is thermal runaway, which is mainly caused by heat—specifically, the exothermic reaction resulting from the gradual thermal decomposition of various substances within the battery, including the SEI film, electrolyte, binder, and positive and negative electrode active materials. 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 battery cell can be categorized into degree-controlled or electrochemical reaction types. Tolerance control can be achieved by 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. As the temperature rises, polymerization occurs, reducing the rate of ion migration and thus decreasing ionic conductivity with increasing temperature, slowing down the electrochemical reaction rate within the lithium 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 lithium battery temperature rises, the electronic insulation capacity increases, reducing the electron transfer capacity between the positive or negative electrode layer and the adjacent current collector layer, thus slowing down the electrochemical reaction rate. 3. Forming a modification layer on the surface of the positive electrode active material. At high temperatures, the modification layer transforms into a dense film, increasing the charge transfer resistance and thus slowing down the electrochemical reaction rate.

[0004] However, the above methods only passively block or inhibit electrochemical electronic or ion conduction pathways, and do not inhibit the fundamental entity driven by thermal runaway.

[0005] In view of this, the present invention proposes a novel lithium secondary battery cell that uses a non-Newtonian fluid electrolyte with sulfur dioxide as a coordinator and lithium tetrachloroaluminate as a salt. The electrolyte can release chlorine (chloride and / or chloride ions) at high temperatures to stabilize the positive and negative electrodes, thereby solving the thermal runaway problem of lithium secondary battery cells. Summary of the Invention

[0006] The main objective of this invention is to provide a lithium secondary battery cell that has a non-Newtonian fluid electrolyte with sulfur dioxide as a coordinator and lithium tetrachloroaluminate as a salt. The non-Newtonian fluid electrolyte fills a sealed space with a minimized amount of fluid, thereby effectively limiting the volatilization of the non-Newtonian fluid electrolyte. Furthermore, the non-Newtonian fluid electrolyte can release chlorine at high temperatures to stabilize the positive and negative electrodes, thus actively suppressing thermal runaway of the lithium secondary battery cell.

[0007] Another objective of this invention is to provide a lithium secondary battery cell in which a ligand clamping region is provided between the material interfaces of the electrochemical reaction system, so as to solve the problem of ion transport caused by the non-Newtonian fluid electrolyte depletion region formed at the interface due to its ultra-strong polarity and extremely low surface tension.

[0008] Another objective of this invention is to provide a lithium secondary battery cell in which a ligand clamping region is provided between the material interfaces of the electrochemical reaction system to reduce the interface separation caused by volume changes during the charging and discharging process of the lithium secondary battery cell, thereby reducing the space formation and saturated vapor pressure fluctuations within the electrochemical system and thus slowing down evaporation.

[0009] Another objective of this invention is to provide a lithium secondary battery cell in which a ligand clamping region is provided between the material interfaces of the electrochemical reaction system to enhance the molecular forces on the non-Newtonian fluid electrolyte, reduce the increase in saturated vapor pressure of sulfur dioxide ligands caused by the heating of the lithium secondary battery cell, and thereby reduce the evaporation of sulfur dioxide ligands.

[0010] To achieve the above objectives, the present invention provides a lithium secondary battery cell, which mainly includes an encapsulation component to form a sealed space; an electrochemical reaction system disposed within the sealed space, comprising a positive electrode active material layer; a negative electrode active material layer opposite to the positive electrode active material layer; an insulating layer located between the positive electrode active material layer and the negative electrode active material layer and electrically insulating the positive electrode active material layer from the negative electrode active material layer, which is formed by stacking inorganic particles and / or fibers; and a non-Newtonian fluid electrolyte filled within the sealed space for transferring the driving ions of the electrochemical reaction system, wherein the non-Newtonian fluid electrolyte is a fluidized form of LiAlCl4 and / or LiGaCl4 salts with sulfur dioxide as a ligand. The aforementioned encapsulation component consists of a positive current collector layer, a negative current collector layer opposite to the positive current collector layer, and a plastic frame. The plastic frame is sandwiched between the positive current collector layer and the negative current collector layer, and its two ends are respectively bonded to the positive current collector layer and the negative current collector layer, thus completely sealing the non-Newtonian fluid electrolyte system in a very small space. At the same time, due to the small space, saturated vapor pressure is easily formed, thereby reducing the volatility of ligands (sulfur dioxide).

[0011] 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

[0012] Figures 1(a) to 1(g) are schematic diagrams of different embodiments of the lithium secondary battery cell of the present invention.

[0013] Figure 2 is a schematic diagram illustrating the location of the ligand clamping region, using the lithium secondary battery cell structure in Figure 1(a) as an example.

[0014] Figure 3(a) is a schematic diagram illustrating the lithium secondary battery cell of the present invention with an aluminum cassette, using the lithium secondary battery cell of Figure 1(a) as an example.

[0015] Figure 3(b) is a cross-sectional view of line segment AA' in Figure 3(a).

[0016] Figure 4 is a schematic diagram of an embodiment of the liquid injection device for the lithium secondary battery cell of the present invention.

[0017] Figure 5 is a schematic diagram of another embodiment of the liquid injection device for the lithium secondary battery cell of the present invention.

[0018] Figure 6 is a schematic diagram of another embodiment of the liquid injection device for the lithium secondary battery cell of the present invention.

[0019] Figure 7 is a schematic diagram of another embodiment of the liquid injection device for the lithium secondary battery cell of the present invention.

[0020] Figure 8 is a schematic diagram of another embodiment of the liquid injection device for the lithium secondary battery cell of the present invention. Detailed Implementation

[0021] To make the advantages, spirit, and features of the present invention more readily apparent, detailed descriptions and discussions will follow with examples. It should be noted that these examples are merely representative embodiments of the present invention and are not intended to limit the implementation methods and scope of protection of the present invention to these examples. The purpose of providing these examples is solely to make the disclosure of the present invention more thorough and easier to understand.

[0022] 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.

[0023] 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.

[0024] Please refer to Figure 1(a), which is a schematic diagram of the structure of a lithium secondary battery cell according to the present invention. As shown in the figure, the lithium secondary battery cell 10 mainly includes an encapsulation component 11, which forms a sealed space 12; and an electrochemical reaction system disposed within the sealed space 12 constructed by the encapsulation component 11. The electrochemical reaction system includes a positive electrode active material layer 14; a negative electrode active material layer 16; an isolation layer 18 located between the positive electrode active material layer 14 and the negative electrode active material layer 16 and electrically insulating the positive electrode active material layer 14 and the negative electrode active material layer 16; and a main electrolyte 17 filled in the remaining space of the electrochemical reaction system to transfer the active ions, lithium, of the electrochemical reaction system. The aforementioned main electrolyte is a non-Newtonian fluid electrolyte with sulfur dioxide as a ligand and lithium tetrachloroaluminate or lithium tetrachlorogallate as a salt. Due to strong ionic forces, under stress (e.g., driven by an electric field), its viscosity decreases, exhibiting liquid-like behavior. However, without stress, it exhibits fluid behavior similar to a polymer gel. This non-Newtonian fluid electrolyte is entirely formed by inorganic ion coordination and can also be called a fluid inorganic electrolyte. The chemical formula of this non-Newtonian fluid electrolyte can be LiAlCl4·x1SO2, LiGaCl4·x2SO2, or both simultaneously, where x1 or x2 can be any number between 1 and 6. For example, when the chemical formula is LiAlCl4·x1SO2, x1 can be 1.5, 3.0, or 4.6, etc. The following description will use LiAlCl4·x1SO2 as an example, but this should not limit the application to LiAlCl4·x1SO2.

[0025] In this case, the positive electrode active material can be a layered lithium oxide containing nickel and manganese, nickel and aluminum, or simultaneously containing nickel, manganese, and aluminum. More preferably, it contains 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 LiNi0.9 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 0.06 Mn 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 can be in the form of a film or sheet of lithium metal, or it can be formed by mixing and coating lithium alloyable material particles with binders and conductive materials.

[0026] The aforementioned isolation layer 18 is used to prevent the positive electrode active material layer 14 from contacting the negative electrode active material layer 16. The isolation layer 18 is formed by stacking inorganic particles and / or fibers using an adhesive. The isolation layer 18 does not have a polymer base film that carries these inorganic particles or fibers, such as a thin film formed from polyolefin materials. The adhesive is selected from PTFE, PAA, PAN, PEI, TPU, PA, PI, P(VDF-TrFE-CFE) poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) with a melting point of 120°C, P(VDF / TrFE) poly(vinylidene fluoride-co-trifluoroethylene) with a melting point of 150°C, PVP with a melting point of 130°C, NBR nitrile butadiene rubber with a depolymerization temperature of 300°C, ethyl cellulose, acrylonitrile and butadiene copolymer, or a mixture of at least two of the above materials. The inorganic particles can be ion-conducting or non-ion-conducting. That is, the material of the inorganic particles can be a solid electrolyte (e.g., oxide solid electrolytes, such as LLZO, LATP, LAGP, LASO, etc.), a passive metal oxide (e.g., Al2O3, TiO2, etc.), a passive nitride (which has fewer -OH, -H, -O- functional groups on the surface, thus exhibiting lower water absorption than metal oxides), or other salt particles (e.g., sulfates, phosphates, or halide salts). These inorganic particles possess two characteristics: first, they do not react with LiAlCl4·x1SO2 chemically or electrochemically; second, they possess high polarity and appropriate functional groups, which do not hinder ligand (SO2 liquid) interactions, and may even enhance them, and they have quite good surface interactions with this specific non-Newtonian fluid electrolyte, making them easy to wet. The pores of the aforementioned isolation layer 18 are nanoscale.

[0027] The insulating layer 18 may further comprise at least one fibrous material, mixed together with inorganic particles, to improve the flexibility and impact resistance of the insulating layer 18, or the insulating layer 18 may be formed directly from a stack of fibrous materials. The fibrous material has a diameter of 2 nm to 50 nm and / or 0.1 μm to 10 μm, and a length of 6 μm to 100 μm (preferably L / D ≥ 7.5). When the total mass of the inorganic particles and the fibrous material is 100%, the proportion of the fibrous material can be 5% to 35%. The fibrous material is selected from at least one of inorganic materials, such as alumina fibers, silica fibers, zirconium dioxide fibers, boron nitride fibers, silicon nitride fibers, boron nitride nanotubes, glass fibers, titanium dioxide nanotubes, and zirconium dioxide nanotubes. Furthermore, the fibrous material may be mixed in three forms: unsintered, partially sintered, and fully sintered. For example, alumina fibers dried at low temperatures (<600℃) still contain organic polymer skeletons such as PVP, PAN, or PEO, as well as A-OH bonds and residual sol moisture. They have no obvious grains and exhibit an amorphous colloidal network structure, which is highly flexible and weaveable. Alumina fibers that are partially sintered (800-1000℃) are mainly composed of γ-Al2O3 nanocrystals and have moderate flexibility (can be bent by tens of degrees). They have higher strength compared to the low-temperature dried type. Alumina fibers that are sintered at high temperatures (>1200℃) are mainly composed of α-Al2O3 nanocrystals. Although they cannot withstand bending stress, they have high strength. Therefore, in the selection and matching ratio of fibers, partially sintered fibers > low-temperature dried fibers > fully sintered fibers are used to obtain a better balance between flexibility and strength. In addition, the strength can be expressed by the material properties of inorganic particles. For example, unsintered silicon nitride fibers are amorphous and contain NH bonds, which can coordinate with sulfur dioxide groups, resulting in good flexibility. After medium-temperature treatment (1000-1200℃), the silicon nitride fibers partially crystallize, becoming semi-flexible. After high-temperature sintering (1400℃), they form α / β-Si3N4 crystals, exhibiting high strength. Therefore, in selecting and mixing fiber ratios, partially sintered fibers > low-temperature dried fibers > fully sintered fibers are preferred to achieve a better balance between flexibility and strength.

[0028] The aforementioned encapsulation component 11 is composed of a positive current collector layer 22, a negative current collector layer 24 opposite to the positive current collector layer 22, and a frame 26. The frame 26 is sandwiched between the positive current collector layer 22 and the negative current collector layer 24, and its two ends are respectively bonded to the positive current collector layer 22 and the negative current collector layer 24. In terms of component position, the aforementioned positive active material layer 14 is exposed on the surface of the positive current collector layer 22 on the sealed space 12, and the aforementioned negative active material layer 16 is exposed on the surface of the negative current collector layer 24 on the sealed space 12.

[0029] One end of the aforementioned adhesive frame 26 is adhered to the remaining area of ​​the first surface 22a of the positive electrode current collector layer 22 where the positive electrode active material layer 14 is not provided, which is generally the periphery of the positive electrode current collector layer 22. The other end of the adhesive frame 26 is adhered to the remaining area of ​​the second surface 24a of the negative electrode current collector layer 24 where the negative electrode active material layer 16 is not provided, which is generally the surrounding area and corresponds to the surrounding area of ​​the positive electrode current collector layer 22. The material of the aforementioned adhesive frame 26 can be selected from materials that do not react with sulfur oxides. For example, highly cross-linked acrylic resins (cross-linking agent content ≥20%) or epoxy resins are good choices. The aforementioned adhesive frame 26 can also be formed by hot-pressing a first adhesive frame layer 261 located in the periphery of the positive electrode current collector layer 22 and a second adhesive frame layer 262 located in the edge region of the negative electrode current collector layer 24, as shown in Figure 1(b). Alternatively, the adhesive frame 26 can also be formed by hot-pressing an adhesive frame layer 263 (see Figure 1(c)) on either or both of the adhesive frames, with adhesive applied to each frame layer and then hot-pressed together to form an intermediate adhesive frame layer 263 to bond the first adhesive frame layer 261 and the second adhesive frame layer 262. The first adhesive frame layer 261 and the second adhesive frame layer 262 have better metal adhesion than the intermediate adhesive frame layer 263. Furthermore, some of the frame 26 can also climb onto the surface of the inner electrode layer (positive electrode active material layer 14, negative electrode active material layer 16, or separator layer 18), so that the sealed space 12 is reduced due to the closer contact between the frame 26 and the inner electrode layer (positive electrode active material layer 14, negative electrode active material layer 16, and separator layer 18). For example, the first frame layer 261 climbs onto the surface of the positive electrode active material layer 14, as shown in Figure 1(d), or the second frame layer 262 climbs onto the surface of the negative electrode active material layer 16, as shown in Figure 1(e), or the second frame layer 262 climbs onto the surface of the separator layer 18, as shown in Figure 1(f). Furthermore, an intermediate frame layer 263 can be provided between the first frame layer 261 and the second frame layer 262. Alternatively, the intermediate frame layer 263 can climb onto the surface of the positive electrode active material layer 14 of the inner electrode layer, as shown in Figure 1(g).

[0030] Furthermore, when the inorganic particles or fibers of the isolation layer are selected from metal oxides, the non-Newtonian fluid electrolyte used in this invention, upon contact with such an isolation layer, will rapidly wet the surface of the inorganic particles or fibers and penetrate into the high surface area pores constructed within the inorganic particles or fibers due to the high polarity and high resistance of the metal oxide powder. Moreover, under the surface tension limitation and surface forces of the inorganic particles or fibers, the strongly coordinating SO2 of the non-Newtonian fluid electrolyte is not easily evaporated. Furthermore, when the aforementioned inorganic metal oxide 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 in other words, having a higher proportion of the α phase.

[0031] In addition, due to the strong polarity and extremely low surface tension of this non-Newtonian fluid electrolyte, it is easy to flow into the pores after the viscosity is reduced under stress. However, it also has a high affinity for each inner electrode layer (positive electrode, negative electrode and separator), which easily forms an inorganic electrolyte vacancy region at the interface, which is not conducive to the movement of ions at the interface. Based on this, it is necessary to form a special region at this interface as an ion channel or bridge so that ions can move freely through the channel formed by strong ion coordination.

[0032] Based on the above, the material interface in the electrochemical reaction system has a coordination clamping region. This material interface can be selected from the interface between the positive electrode active material layer and the insulating layer, the interface between the negative electrode active material layer and the insulating layer, the interface between the active material particles of the positive electrode active material layer, the interface between the active material particles of the negative electrode active material layer, the interface between the inorganic particles or fibers of the insulating layer, or at least two or more of the above. The coordination clamping region can be an ionic coordination structure formed by a first polymeric polycationic electrolyte and a strong ligand (sulfur dioxide) in the non-Newtonian fluid electrolyte, which can increase the concentration of SO2 in this region. Simultaneously, this polymeric polycationic electrolyte can be distributed across the various interfaces mentioned above. This polymeric polycationic electrolyte can be compounded and embedded in the separator, positive electrode, or negative electrode active material layer. The functional groups of the cationic groups in the first polymeric polycationic electrolyte are located on the main chain and / or side chains, thus forming immobile cationic groups at the interface. Due to ion coordination, these immobile cationic groups will adsorb more SO2, resulting in a higher concentration of SO2. This can be considered as an ion coordination channel for lithium ions, or as a solvent carrier composed of ligands facilitating the movement of lithium ions at the interface of the inner electrode layer. In the schematic diagram of Figure 2, the clamping region 28 is shown at the interface between the positive electrode active material layer 14 and the separator 18, and at the interface between the negative electrode active material layer 16 and the separator 18. Figure 2 is an example of the battery cell architecture of Figure 1(a), but those skilled in the art will understand that this does not limit the ligand clamping region to only the battery cell architecture of Figure 1(a), but rather it can be widely applied to various battery cell architectures proposed in this application.

[0033] The functional groups of the aforementioned polymeric polycationic electrolyte can dissolve or swell, and are wetted by SO2. Furthermore, because the main chain and / or side chain of the polymeric polycationic electrolyte itself have cationic groups, and the ligand (or solvent) SO2 of the non-Newtonian fluid electrolyte is a highly polar material with lone pairs of electrons, it is easy to form dipole bonds next to the lone pairs of electrons of the cation and SO2, thereby retaining this non-Newtonian fluid electrolyte and forming a capturing region, which acts as a bridge or channel, allowing ions to move freely through the solvent.

[0034] This differs from liquid organic electrolytes. The forces between organic electrolyte molecules are stronger than those between the counter-electrode layer and the separator layer. Therefore, the solvent channels at the interface do not disappear, and only a pressure is needed to maintain or maintain these channels. This pressure can come from the mechanical stress of winding or from organic polymers, such as PVDF-HFP coated on the separator layer surface. With the liquid organic electrolyte acting as a plasticizer, the softening point of the polymer is lowered. At a lower temperature, external pressure is applied, causing physical entanglement with the positive and negative electrode layers, resulting in adhesion and a force that brings the positive and negative electrodes into contact with the separator layer. In this case, regardless of the expansion or contraction of the electrode layers, as long as the organic electrolyte is in contact, it is sufficient. Therefore, the inherent properties of the organic electrolyte do not create electrolyte vacancies.

[0035] However, the polarity of non-Newtonian fluid electrolytes is too strong, which makes it too easy for them to come into contact and wet with inorganic particles or fibers in the positive and negative electrode active material layers and the isolation layer. At the same time, the viscosity increases under no stress, which makes it difficult for ions to move at the interface. Therefore, even under pressure, non-Newtonian fluid electrolytes will form vacant regions or partial discontinuities at the interface, resulting in increased interfacial resistance and poor ion conductivity. Therefore, by forming a ligand clamping region between the aforementioned polymeric polycationic electrolyte and the non-Newtonian fluid electrolyte, while the polymeric polycationic electrolyte remains a polymer, under the swelling and expansion of the non-Newtonian fluid electrolyte, the polymeric polycationic electrolyte will bond with the electrode layer or isolation layer, whether it is active material particles, conductive material or adhesive polymer, to form a bridge-like structure. This polymeric polycationic electrolyte can be directly placed on the interface, or directly placed in the two electrode layers and isolation layers, or only on one electrode layer / isolation layer. At the interface, because the polycationic functional groups on the main chain and / or side chain of the polymeric polycationic electrolyte form a strong ionic coordination structure with the non-Newtonian fluid electrolyte, such a structure can form a relatively weak ionic coordination cross-linking structure, while maintaining a certain degree of adhesion, and at the same time enhancing the ability of this inorganic electrolyte system to adapt to the expansion and contraction (cycle life) of the positive and negative electrode active material layers.

[0036] Furthermore, negative electrode active materials that exhibit weak dipole forces with non-Newtonian fluid electrolytes expand significantly during the charging and discharging process of lithium secondary battery cells, such as silicon-lithium alloys. Although this non-Newtonian fluid electrolyte easily wets the surface of the active material, once it expands and contracts, it can easily move to other places due to the influence of other inactive materials, creating a depletion region. This still has a negative impact on the charge transfer of active materials with a high expansion ratio. Therefore, setting this polymeric polycationic electrolyte in the positive and negative electrode layers (active material layers) can produce a better depletion region suppression effect. This polymeric polycationic electrolyte will contact the active material and form adhesion points (bridges) and form good ion channels. At the same time, it reduces the deformation of the surface and pores of the electrode layer and the separator caused by the volume change of the active material in the electrode layer, which causes changes in the distribution of non-Newtonian fluid electrolyte and the resulting electrolyte discontinuity, thereby enhancing the ion movement and charge transfer ability of the active material surface.

[0037] Polycationic electrolytes are polymeric electrolytes or oligomeric electrolytes that contain cationic groups in the main chain or side chain of a polymer, or both. Examples are as follows:

[0038] Type I: Pyrrolidine polymer electrolytes, whose structure may be:

[0039] Although the above chemical formula uses FSI- as the para anion, other para anions, such as TFSI-, can also be used. - BOB - DFOB - BF4 - Cl - or I - .

[0040] Type II: Quaternary ammonium salt polyelectrolytes, characterized by the presence of quaternary ammonium groups (-NR4). + ), where R is typically alkyl or aryl. Examples include: polydimethyldiallylammonium chloride (PolyDADMAC) or poly(N-vinylpyrrolidone-quaternized ammonium chloride).

[0041] Type III: Guanidinyl polyelectrolytes, characterized by the presence of a guanidinyl group (-C(=NH)-NH2). + For example: polyethyl guanidine (PEG) or polyhexamethylene guanidine (PHMG).

[0042] Type IV: Imidazolium-containing polyelectrolytes, which contain imidazolium groups (-Im +), is obtained through the cationization of imidazole. For example, poly(1-vinyl-3-alkylimidazolium salt).

[0043] Type 5: Amine polyelectrolytes, characterized by the presence of primary amines (-NH2), secondary amines (-NH-), or tertiary amines (-NR3). + For example, polyethyleneimine (PEI) or cationic cellulose derivatives.

[0044] Type VI: Phosphorus-containing cationic polyelectrolytes, characterized by the presence of positive phosphorus ion groups (-PR3). + For example, polymers modified with phosphonium salts.

[0045] Type 7: Polyelectrolytes containing pyridine salts, characterized by the presence of cationized pyridine groups (-C5H5N). + For example, poly(4-vinylpyridine) cationic products.

[0046] Type 8: Zwitterionic polyelectrolytes, characterized by the presence of both cationic and anionic groups, with the cationic portion being the primary functional group. For example, sulfobetaines (polymers containing sulfonic acid and ammonium groups).

[0047] Meanwhile, the ligand clamping region can also be formed by polymers or oligomers with proton donor functional groups (functional groups are present in the main chain, side chain, or both) and non-Newtonian fluid electrolytes, as shown in the following examples (mainly mentioning the relevant functional groups):

[0048] Common functional groups that carry proton donors include carboxyl (-COOH), sulfonic acid (-SO3H), phosphate (-PO3H2), alcohol hydroxyl (-OH, under certain special conditions), phenolic hydroxyl (-ArOH, aromatic hydroxyl), or amino (-NH3). + Polymers with carboxyl groups (-COOH) include polyacrylic acid (PAA) or polymethacrylic acid (PMAA). Polymers with sulfonic acid groups (-SO3H) include polystyrene sulfonic acid (PSSA) or Nafion (a perfluorosulfonic acid polymer). Polymers with phosphate groups (-PO3H2) include polyphosphate esters or phosphorylated polymers. Polymers with phenolic hydroxyl groups (-ArOH, aromatic hydroxyl groups) include polyphenols.

[0049] Common examples of monomers include organic acids, such as acrylic acid (CH2=CHCOOH), methacrylic acid (CH2=C(CH3)COOH), or benzoic acid (C6H5COOH); sulfonic acids, such as styrene sulfonic acid (CH2=CHC6H4SO3H); phosphoric acids, such as phosphate ester monomers (e.g., 2-hydroxyethyl methacrylate phosphate); or amines, such as pyrrole (C4H5N, which can be protonated under acidic conditions) or pyridines containing protonated amine groups (e.g., pyridinium salts). Oligopolymers are molecules formed by the polymerization of a small number of monomers, retaining the proton donor group. For example, carboxyl oligomers can be oligoacrylic acid or oligomethacrylic acid; sulfonic acid oligomers can be oligostyrene sulfonic acid; and phosphate oligomers can be oligophosphate esters.

[0050] For example, when a pyrrolidine polymer electrolyte is added as a polycationic electrolyte in the separator, the coordination clamping region formed by the pyrrolidine polymer electrolyte and the non-Newtonian fluid electrolyte provides adhesion between the positive electrode active material layer and the separator. Compared to lithium secondary battery cells without coordination clamping regions, the internal impedance of the battery cell can be reduced by approximately 40%, assuming all other material parameters within the battery cell remain the same. The relevant parameters and conditions for this test are as follows: Before measuring ACIR (AC internal resistance), the battery cell is charged to 4.2V with a constant current, and then charged at a constant voltage of 4.2V until the current is ≤0.06C. The testing instrument is a Hiokki 3562, frequency: 1kHz, function: ΩV, sampling time: Slow.

[0051] In the battery cell architecture of this case, the entire electrochemical reaction system (positive electrode active material layer 14, separator layer 18 and negative electrode active material layer 16) is located in the sealed space 12 formed by the encapsulation structure 11. Since it is a sealed space, the electrochemical reaction system (or inner electrode layer (positive and negative electrode layers and ceramic separator)) is completely sealed by the upper and lower current collector layers and the surrounding frame adhesive. Therefore, the battery cell 10 of this case can also have another encapsulation structure, which can be a bag-shaped covering layer formed by aluminum-plastic film, referred to here as aluminum pack 29. The battery cell 10 is encapsulated by aluminum pack 29 to form a lithium secondary battery 27 as shown in Figures 3(a) and 3(b). A vacuum can be drawn when aluminum pack 29 is sealed, so that the space between the aluminum pack and the encapsulation component 11 of the battery cell 10 is in a negative pressure state. If the encapsulation component 11 is lacking to form such a sealed space 12 to protect the electrochemical reaction system, and instead the open structure of a conventional lithium battery is used, vacuuming is impossible because the SO2 ligands in the non-Newtonian fluid electrolyte have a high vapor pressure. Therefore, vacuuming can only be performed under the sealed structure of this invention, and even vacuuming can be performed while pressing, increasing the vacuum level and allowing the pressure of the aluminum cladding 29 to approach 1 atm. This results in better contact between the inner electrode layers, and each layer is connected by a bonding mechanism constructed through the ligand clamping regions (whether formed by direct coating). The adhesive interface, or the polymer electrolyte with cationic groups and the inorganic electrolyte are bonded together by ionic coordination to form an ionic cross-linking structure, means that the stress changes caused by volume changes will not cause the layers to separate in the electrochemical reaction system of this invention. No space will be formed, thus the surface saturated vapor pressure will not decrease, thereby slowing down evaporation. Simultaneously, because the strong ionic coordination has a powerful molecular force on the non-Newtonian fluid inorganic electrolyte, it also reduces the increase in saturated vapor pressure within the cell system due to temperature rise, thereby reducing the amount of SO2 evaporation. Furthermore, the remaining free space within the cell structure (closed space 12) of the lithium secondary battery of this invention (without filling material) is significantly low or almost non-existent. Therefore, even if the temperature of the lithium secondary battery cell increases under normal operation, only a very small amount of SO2 will evaporate to reach the saturated vapor pressure, forming a gas-liquid phase equilibrium. For non-Newtonian fluid electrolytes with SO2 as the coordinator, the SO2 content is a crucial factor affecting ion conductivity. Therefore, in the battery cell architecture of this invention, the SO2 content does not fluctuate significantly, thus maintaining stable and relatively good ion conductivity, enabling the lithium secondary battery cell to operate normally. Figure 3(a) is an illustration using the battery cell architecture of Figure 1(a) as an example. However, those skilled in the art will understand that this does not limit the aluminum cladding to only the battery cell architecture of Figure 1(a), but rather it can be widely applied to various battery cell architectures proposed in this invention.

[0052] Furthermore, LiAlCl4 decomposes at temperatures between 120°C and 200°C to form chlorides, such as LiCl or AlCl3. AlCl3 releases chloride ions at high temperatures, but the release of chloride ions is facilitated in the presence of SO2 because the lone pair of electrons in SO2 can react with AlCl3. 3+ This forms weak coordination bonds, allowing AlCl3 to easily partially dissociate and release Cl. - Increasing the chloride ion content leads to a greater number of free chloride ions, which then enter the unstable cathode active material crystals at high temperatures. These ions occupy the lithium-deficient (original lithium atom) positions within the cathode active material, and subsequently form strong coordination bonds with O, Ni, Co, and Mn in the cathode active material, stabilizing its crystal structure and preventing the release of O at high temperatures. Furthermore, the solvent properties of SO2 facilitate the movement of chloride ions, ensuring their stable movement within the SO2-containing solvent environment. Additionally, SO2 reduces the electrostatic repulsion of chloride ions entering the cathode active material, making the intercalation process easier.

[0053] At the negative end, when the lithium secondary battery cell decomposes LiAlCl4·x1SO2 due to high temperature, the Cl produced will react with the negative electrode active material that has already formed an alloy with Li, such as silicon, to form a stable Li-Si-Cl alloy. In addition, under the combined effect of AlCl4 and SO2, LiCl will partially dissolve, thereby enhancing the continuous entry of chloride ions into the Si-Li alloy and suppressing thermal runaway.

[0054] Furthermore, in order to apply the non-Newtonian fluid electrolyte of the present invention to the surface of the separator 18 and / or the positive and negative polarity material layers 14, 16 (also referred to as the half-cell 101) or the surface of the ligand clamping region 28, a liquid injection carrier 30 is proposed to increase the airtightness during liquid injection and prevent SO2 volatilization. Please refer to FIG4, which shows the liquid injection device 30 injecting liquid into the half-cell 101 of the lithium secondary battery cell of the present invention with the end face of the negative polarity active material layer 16 having the separator 18 as an example. The same logic can be deduced for the positive terminal on the other side, so it will not be described again in this description.

[0055] The liquid injection device 30 includes a guide tube 31 and a liquid injection distributor 32. One end of the guide tube 31 is connected to a material mixing tank (not shown), and the other end is connected to the liquid injection distributor 32. The liquid injection distributor 32 has a joint 321 and a guide section 322 connected to the joint 321. The joint 321 has a liquid injection tank 3211, and the guide section 322 has several small-diameter liquid injection holes 3221 that communicate with the liquid injection tank 3211. The joint 321 has a stronger structural rigidity than the guide section 322 to withstand the liquid injection process of the guide tube 31 and the pressure difference of the non-Newtonian fluid electrolyte entering the liquid injection hole 3221. The guide section 322 is made of an elastic material that can be slightly deformed, such as Teflon, to increase the airtightness between the liquid injection carrier 30 and the surface of the isolation layer 18 and reduce the volatilization of SO2. In addition, the surface of the guide section 322 adjacent to the positive or negative terminal of the battery cell can be non-polar to facilitate the injection of non-Newtonian fluid electrolyte to the positive or negative terminal.

[0056] Furthermore, as shown in Figure 5, the injection carrier 30 may also include a cover 34, on which a sealing gasket 341 is provided on the surface facing the isolation layer 18. During the injection of inorganic electrolyte, the sealing gasket 341 will abut against the second rubber frame 262, so that the part of the guide portion 322 in contact with the isolation layer 18 is in a sealed state to the external environment, thereby maintaining the hydraulic stability of the non-Newtonian fluid electrolyte.

[0057] Please refer to Figure 6. The difference between Figure 6 and Figure 4 is that the flow guide 322 and the isolation layer 18 of the lithium secondary battery cell have a gap (distance). Therefore, the non-Newtonian fluid electrolyte droplets 39 flowing out from the flow guide 3221 seep into the half-cell cell 101 under the influence of gravity and the capillary attraction of the half-cell.

[0058] Please refer to Figure 7, which is a schematic diagram of another liquid injection device. As shown, this liquid injection device 40 includes a guide pipe 41, a liquid injection distributor 42, and a sealing cover 46. One end of the guide pipe 41 is connected to a material mixing tank (not shown), and the other end is connected to a liquid injection distributor 42. The liquid injection distributor 42 has a joint 421 and a support platform 422 connected to the joint 421. The joint 421 has a liquid injection tank 423, and the support platform 422 has several liquid injection holes 425 that can communicate with the liquid injection tank 423. The area where these liquid injection holes 425 are located is defined as the liquid injection zone 424. The surface of the support platform 422 adjacent to the end of the half-cell 101 of the lithium battery cell can be non-polar to facilitate the injection of non-Newtonian electrolyte into the half-cell 101. A sealing gasket 43 is further provided on the support platform 422 outside the injection area 424, so that when the sealing cover 46 is placed on the support platform 422, a sealed space 47 can be formed between the sealing cover 46 and the support platform 422 to accommodate the half-cell 101. Furthermore, the second frame 262 of the half-cell 101 will abut against the portion of the sealing gasket 43 that is not in contact with the sealing cover 46. As shown in the figure, in this embodiment, the open end of the half-cell 101 faces downwards. Therefore, after the non-Newtonian electrolyte forms a droplet 39 from the injection hole 425, the droplet 39 will be injected into the half-cell 101 by the capillary force of the half-cell 101 and the material properties of the SO2 electrolyte itself. In this embodiment, the size of the liquid droplet 39 is crucial. A droplet 39 that is too large will, due to its own gravity, resist the capillary force of the upper electrode layer, thus reducing the amount of non-Newtonian electrolyte absorbed by the electrode layer. Therefore, a smaller droplet 39 is used. However, if the droplet 39 is too small, it is difficult to provide a sufficient quantity. Therefore, smaller droplets 39 can only achieve the same total amount provided by a larger droplet in the same time period by using a greater number of injection holes. However, if the outlet holes are arranged too close together, these small droplets 39 may collide or come into contact with each other. However, when small liquid droplets 39 are used, the original setting of the small liquid droplets 39 is lost. In addition, when small liquid droplets 39 are used, the distance (or height) between the injection hole 425 and the half-cell cell 101 can be shorter (or lower) compared to large liquid droplets. That is, the contact space between the liquid droplet 39 and the electrode layer after leaving the injection hole 425 can be very small. All of this indicates that when using small liquid droplets 39, the processing precision requirements of the injection device are higher, so that the small liquid droplets 39 have their most appropriate volume and solution amount, for example, 1 to 5 μL.

[0059] Furthermore, in this embodiment, the injection holes 425 of the injection area 424 may be arranged in a staggered manner to increase the density of the injection holes 425 in the injection area 424. The inner surface of the sealing cover 46 may also have an elastic pressing member 461 to press against the half-cell cell 101 disposed in the sealed space 47, so that the second rubber frame 182 and the sealing gasket 43 have better contact and tightness.

[0060] Please refer to Figure 8. The difference between Figure 8 and Figure 7 is that the support platform 422, outside the injection area 424, is further provided with a sealing gasket 43 and a sealing gasket 48. The sealing gasket 43 is used to create a sealed space 47 between the sealing cover 46 and the support platform 422 when the sealing cover 46 is placed on the support platform 422, to accommodate half of the battery cell 101. The sealing gasket 48 abuts against the second rubber frame 262 of the half-cell 101. The sealing gaskets 43 and 48 can be made of the same or different materials.

[0061] In summary, this invention proposes a lithium secondary battery cell with an encapsulation component formed by a positive electrode current collector layer, a negative electrode current collector layer, and a frame to encapsulate an electrochemical reaction system using lithium tetrachloroaluminate as the salt and sulfur dioxide as a strong coordinator, which is a non-Newtonian fluid inorganic electrolyte. This minimizes the remaining space within the lithium secondary battery cell, allowing only a trace amount of coordinators to evaporate to reach saturated vapor pressure and achieve gas-liquid phase equilibrium. This effectively prevents the separation of coordinators and the salt, maintaining the normal operation of the lithium secondary battery cell. Furthermore, this invention has a coordinator clamping region at at least one of the material interfaces in the electrochemical reaction system, effectively solving the problem of non-Newtonian fluid electrolyte depletion regions caused by the ultra-strong polarity and extremely low surface tension of this non-Newtonian fluid electrolyte. This further ensures that the lithium secondary battery cell of this invention does not experience layer-to-layer separation during volume changes during charging and discharging, effectively preventing a decrease in surface saturated vapor pressure. In addition, this non-Newtonian fluid electrolyte decomposes on its own at 120°C to 200°C to form chlorides and passivate the positive and negative electrode active materials, effectively solving the problem of thermal runaway in lithium secondary batteries.

[0062] The description provided is merely a preferred embodiment of the present invention and is not intended to limit the scope of the invention. Therefore, all equivalent variations or modifications made in accordance with the features and spirit described in the claims of the present invention should be included within the scope of the claims.

[0063] Explanation of reference numerals in the attached figures

[0064] 10 Lithium-ion secondary battery cells

[0065] 101 half-cell battery

[0066] 11. Encapsulation components

[0067] 12 Enclosed Spaces

[0068] 14 Positive electrode active material layer

[0069] 16. Negative electrode active material layer

[0070] 17. Non-Newtonian fluid electrolytes

[0071] 18 Isolation Layers

[0072] 22 Positive current collector layer

[0073] 22a First Surface

[0074] 24 Negative electrode current collector layer

[0075] 24a Second Surface

[0076] 26 Frame

[0077] 261 First frame layer

[0078] 262 Second frame layer

[0079] 263 Intermediate Frame Layer

[0080] 28 Coordinator Clamping Regions

[0081] 29 Aluminum cladding

[0082] 30 Injection Carriers

[0083] 31. Flow guide tube

[0084] 32 Injection Diverter

[0085] 321 Joint

[0086] 3211 Injection Tank

[0087] 322 Airflow Guide

[0088] 3221 Guide Channel

[0089] 34. Cover

[0090] 341 Sealing gasket

[0091] 39 liquid droplets

[0092] 40 liquid injection device

[0093] 41. Flow guide tube

[0094] 42 Injection Diverter

[0095] 421 Joint

[0096] 422 Support Platform

[0097] 423 Injection Tank

[0098] 424 Injection Area

[0099] 425 Injection Hole

[0100] 43 Sealing gasket

[0101] 46 Sealing Cover

[0102] 461 with elastic pressure-resistant components

[0103] 47. Enclosed space

[0104] 48 Sealing gaskets

Claims

1. A lithium secondary battery cell, comprising: An encapsulation component comprises a positive current collector layer, a negative current collector layer opposite to the positive current collector layer, and an adhesive frame. The adhesive frame is sandwiched between the positive and negative current collector layers and its two ends are respectively bonded to the positive and negative current collector layers. The encapsulation component forms a sealed space. An electrochemical reaction system, contained within the sealed space, the electrochemical reaction system comprising: A positive electrode active material layer is disposed on the positive electrode current collector layer; A negative electrode active material layer is disposed on the negative electrode current collector layer; An insulating layer is located between the positive electrode active material layer and the negative electrode active material layer to prevent contact between the two layers. This insulating layer is primarily composed of stacked inorganic particles and / or inorganic fibers. A non-Newtonian fluid electrolyte, which is filled in the sealed space and used to transfer the driving ions of the electrochemical reaction system, wherein the non-Newtonian fluid electrolyte is an electrolyte that uses sulfur dioxide as a ligand and fluidizes LiAlCl4 and / or LiGaCl4.

2. The lithium secondary battery cell according to claim 1, wherein a portion of the adhesive frame extends to cover a portion of the surface of the positive electrode active material layer, the surface of the negative electrode active material layer, or the surface of the separator layer.

3. The lithium secondary battery cell according to claim 1, wherein the material interface in the electrochemical reaction system has a ligand clamping region, and the material interface in the electrochemical reaction system is selected from the interface between the positive electrode active material layer and the separator layer, the interface between the negative electrode active material layer and the separator layer, the interface between the active material particles of the positive electrode active material layer, the interface between the active material particles of the negative electrode active material layer, the interface between the inorganic particles and / or inorganic fibers of the separator layer, or at least two or more of the above.

4. The lithium secondary battery cell according to claim 3, wherein the ligand clamping region is an ion coordination structure formed by the ligand of a polymeric polycationic electrolyte and the non-Newtonian fluid electrolyte.

5. The lithium secondary battery cell according to claim 4, wherein the polymeric polycationic electrolyte is selected from polymeric electrolytes or oligomeric electrolytes whose main chain and / or side chains have cationic groups.

6. The lithium secondary battery cell according to claim 5, wherein the polymeric polycationic electrolyte is selected from pyrrolidine polymer electrolytes, quaternary ammonium salt polyelectrolytes, guanidine polyelectrolytes, imidazolium-containing polyelectrolytes, amino polyelectrolytes, phosphorus-containing cationic polyelectrolytes, pyridine salt-containing polyelectrolytes, or zwitterionic polyelectrolytes with cationic as the main function.

7. The lithium secondary battery cell according to claim 3, wherein the ligand clamping region is an ionic coordination structure formed by a polymer or oligomer with a proton donor functional group and the ligand of the non-Newtonian fluid electrolyte.

8. The lithium secondary battery cell according to claim 7, wherein the proton donor functional group is selected from carboxyl (-COOH), sulfonic acid (-SO3H), phosphoric acid (-PO3H2), alcoholic hydroxyl (-OH), phenolic hydroxyl (-ArOH, aromatic hydroxyl) or amino (-NH3) groups. + (protonated state).

9. The lithium secondary battery cell according to claim 1, wherein the inorganic particles are selected from solid electrolytes with ion conductivity, metal oxides, nitrides or salts without ion conductivity, or a mixture of at least two of the above materials.

10. The lithium secondary battery cell according to claim 1, wherein an adhesive portion is provided between the inorganic particles and / or the inorganic fibers to bond adjacent inorganic particles and / or inorganic fibers, wherein the material of the adhesive portion is selected from PTFE, PAA, PAN, PEI, TPU, PA, PI, poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) with a melting point of 120°C, poly(vinylidene fluoride-co-trifluoroethylene) with a melting point of 150°C, PVP with a melting point of 130°C, nitrile rubber with a depolymerization temperature of 300°C, ethyl cellulose, acrylonitrile and butadiene copolymer, or a mixture of at least two of the above materials.

11. The lithium secondary battery cell according to claim 1, wherein the non-Newtonian fluid electrolyte is LiAlCl4·xSO2, where x is any number between 1 and 6.

12. The lithium secondary battery cell according to claim 11, wherein x is 1.5, 3.0 or 4.

6.

13. The lithium secondary battery cell according to claim 1, wherein the inorganic particles and / or fibers are chemically and electrochemically inert with the non-Newtonian fluid electrolyte, and the inorganic particles and / or fibers are polar and / or have functional groups on their surface that can generate affinity with the ligands of the non-Newtonian fluid electrolyte.

14. The lithium secondary battery cell according to claim 1, wherein the material of the frame is selected from highly cross-linked acrylic resin or epoxy resin.

15. The lithium secondary battery cell according to claim 1, comprising an aluminum cassette sealed over the outer surface of the encapsulation component, wherein the aluminum cassette is under negative pressure.

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