Aluminosilicate additive and synthesis method thereof, lithium battery and electronic equipment

Abstract

The invention relates to the technical field of lithium batteries, in particular to an aluminosilicate additive, a synthesis method, a lithium battery and electronic equipment. Wherein the additive is amorphous or partially amorphous aluminosilicate containing sodium ions and potassium ions; wherein the molar ratio of sodium to potassium in the aluminosilicate is (0.1: 1)-(10: 1), and the molar ratio of silicon to aluminum is (1: 1)-(20: 1). On the first aspect, in an aluminosilicate structure, Na < + > / K < + > is used as charge compensation cations to be embedded into cavities or interlayers of an aluminosilicate network, so that a skeleton structure is stabilized, and stress or electrolyte erosion in electrochemical circulation is resisted; on the second aspect, due to existence of Na < + > / K < + >, surface charge distribution, Lewis acid-base property or surface energy of the additive can be changed, interaction of the additive with an active material, a binder or an electrolyte component is influenced, and formation of a more stable interface layer with better ionic conductivity is promoted; in a third aspect, the aluminosilicate additive may also improve lithium ion transport.

Description

Technical Field

[0001] This invention relates to the field of lithium battery technology, and in particular to an aluminum silicate additive and its synthesis method, a lithium battery, and an electronic device. Background Technology

[0002] As the mainstream electrochemical energy storage device, lithium-ion batteries have seen significant research focus on improving their energy density, power density, cycle life, and safety. The electrode-electrolyte interface, electrode material structural stability, and ion transport are key factors determining battery performance. Additives are functional substances added in small amounts during electrode preparation or electrolyte formulation to improve one or more battery properties, such as interface stability and safety. However, currently, there is a lack of multifunctional additives that can simultaneously provide good interface compatibility, high inherent stability, and optimize lithium-ion behavior through specific elemental regulation, thus comprehensively optimizing battery performance. Summary of the Invention

[0003] To address the lack of a multifunctional additive in the prior art that can simultaneously provide good interface compatibility, high stability, and optimize lithium-ion behavior through specific element regulation, this invention provides an aluminum silicate additive and its synthesis method, as well as a lithium battery and electronic device.

[0004] To address the aforementioned technical problems, this invention provides an aluminosilicate additive and its synthesis method, a lithium battery, and an electronic device. The additive is an amorphous or partially amorphous aluminosilicate containing sodium and potassium ions; wherein the molar ratio of sodium to potassium in the aluminosilicate is from 0.1:1 to 10:1, and the molar ratio of silicon to aluminum is from 1:1 to 20:1. Preferably, the particle size of the aluminosilicate additive is 50nm-500nm.

[0005] Preferably, the aluminosilicate additive has a mesoporous or microporous structure with a specific surface area of ​​20 m² / g to 300 m² / g.

[0006] To address the aforementioned technical problems, this invention also provides a solution-gel synthesis method for an aluminosilicate additive. The method involves hydrolyzing a silicon source under acid catalysis to obtain a silica sol; dissolving an aluminum source, a sodium source, and a potassium source in a solvent to obtain a salt solution, wherein the content of the silicon source and the aluminum source are in a certain proportion, and the content of the sodium source and the potassium source are in a certain proportion; adding the salt solution dropwise to the silica sol and adjusting the pH to 7-9 to form a gel; aging the gel, followed by washing and drying, to obtain the aluminosilicate additive as described above.

[0007] Preferably, the drying process further includes the following steps: drying the washed gel in an oven at 80℃-120℃ to obtain a dried product; and heat-treating the dried product in air or an inert atmosphere at 300℃-800℃ for 2 hours.

[0008] To solve the above-mentioned technical problems, the present invention also provides a hydrothermal synthesis method for aluminosilicate additives, wherein a certain proportion of silicon source, aluminum source, sodium source and potassium source are dissolved in a solvent to form a precursor mixture; The precursor mixture was subjected to a hydrothermal reaction at 120°C-250°C to obtain a solid-liquid product; after cooling the solid-liquid product, it was filtered to obtain a solid product; the solid product was washed and dried to obtain the aluminosilicate additive as described above.

[0009] To address the aforementioned technical problems, the present invention also provides a lithium battery comprising an electrode and a solid electrolyte. The electrode comprises a positive electrode and a negative electrode. At least one of the electrode, positive electrode, negative electrode, and solid electrolyte contains an aluminosilicate additive as described above. The aluminosilicate additive serves as a filler in the electrode slurry and / or serves as a coating layer for the positive and / or negative electrode active materials and / or serves as an active / inactive filler in the solid electrolyte.

[0010] To address the aforementioned technical problems, the present invention also provides an electronic device, which includes the lithium battery described above; the electronic device is any one of a mobile phone, tablet, electric vehicle, or smart wearable device.

[0011] The aluminosilicate additive and synthesis method, lithium battery, and electronic device provided by this invention have the following beneficial effects: 1. This invention provides an aluminosilicate additive, primarily composed of silicon (Si), aluminum (Al), and oxygen (O) forming a stable aluminosilicate network structure, with the Si to Al molar ratio adjustable over a wide range. By adjusting the molar ratio of silicon and aluminum in the aluminosilicate additive framework, its intrinsic network structure and surface properties can be precisely altered. A lower Si to Al molar ratio leads to an increase in the negative charge density within the additive framework, which enhances its chemical affinity and physical bonding with electrode materials and electrolyte components, thereby promoting the formation of a more stable and compatible interface. This optimized interface is expected to effectively suppress harmful side reactions, thereby improving the overall stability of the battery and extending its cycle life. Conversely, a higher Si to Al molar ratio forms a more chemically inert and structurally robust silicate network. This enhanced mechanical integrity provides crucial structural support for the electrode, effectively mitigating the stress caused by material volume changes during electrochemical cycling, thus helping to maintain the stability and durability of battery performance. Precise control of the Si to Al molar ratio allows the functional properties of the additive to be customized and optimized for different battery material requirements, ultimately comprehensively improving battery performance and lifespan.

[0012] Furthermore, in the aluminosilicate additive provided by this invention, the molar ratio of Na to K is 0.1:1 to 10:1, which can stabilize the structure, regulate the interface, and enhance lithium-ion transport. Firstly, in the aluminosilicate structure, the introduction of sodium (Na) and potassium (K) mainly plays a dual role as charge-compensating cations and network modifiers. When trivalent aluminum (Al... 3+ Partially replaces tetravalent silicon (Si) 4+ This forms a three-dimensional disordered network framework composed of interconnected silicon-oxygen tetrahedra and aluminum-oxygen tetrahedra, generating localized negative charges. (Na) + and K + By occupying cavities or channels in the network framework, the entire network structure is electrostatically stabilized. Simultaneously, the introduction of Na and K can break some bridging oxygen bonds (Si-O-Si), forming non-bridging oxygen bonds (Si-O). － -M + (M=Na,K), which reduces the polymerization degree of the aluminosilicate network and affects its amorphous properties. Secondly, the presence of non-bridged oxygen bonds and their interaction with Na... + / K +The ionic bonding characteristics of the additive give its surface unique Lewis acid-base sites. These sites can generate stronger chemical interactions with functional groups on the surface of the electrode active material or polar groups of the binder, such as acid-base interactions and hydrogen bonds, enabling it to achieve good physical wetting and / or interfacial chemical interactions with the surface of lithium battery electrode active material particles, conductive agents, binders, or solid electrolyte matrix. This is the microscopic source of the "adhesive" property of this invention, thereby improving interfacial compatibility. Thirdly, when Na... + and K + When coexisting, due to their different ionic radii and electric field strengths, they will form cation-occupying sites of varying sizes and energies within the network. This irregular energy topology will significantly inhibit Na+ cations. + and K + The migration of these alkali metal ions, known as the "mixed alkali effect," firmly anchors them within the framework, preventing easy dissolution or migration during battery cycling and thus ensuring the high chemical stability of the additive's structure. These anchored alkali metal ions and the resulting electrostatic field further influence the surrounding Li... + The transport pathways and dynamics of lithium ions provide the possibility for regulating lithium-ion behavior.

[0013] The aluminosilicate additive of this invention has an amorphous or partially amorphous structure. Understandably, the amorphous network structure of the additive endows it with unique mechanical flexibility, enabling it to effectively mitigate volume changes in the active material when used as a coating layer. Unlike crystalline materials with rigid lattices, the amorphous network lacks long-range order and tight periodic stacking, resulting in more free volume and space for atomic rearrangement. Therefore, when the internal active material (such as a silicon anode) undergoes significant volume expansion, this flexible amorphous coating layer can effectively absorb and dissipate stress through its own plastic deformation, thereby maintaining its structural integrity. This stress buffering mechanism not only continuously protects the active material from electrolyte corrosion but also utilizes its "gluing" properties to bind potentially pulverized particles in situ, ensuring continuous electrical contact between particles and between particles and the conductive network.

[0014] 2. In this invention, the particle size of the aluminosilicate additive is further limited to 50nm-500nm, controlling the particle size of the aluminosilicate to be 50nm-500nm. On the one hand, this particle size range can avoid the problem that nanoscale particles smaller than 50nm are prone to agglomeration due to excessively high surface energy, requiring the addition of a large amount of dispersant to maintain stability, while avoiding the disadvantages of micron-sized particles larger than 500nm being prone to sedimentation and stratification, and difficult to disperse uniformly; on the other hand, a particle size of 50nm-500nm can provide a reasonable spatial framework for the subsequent construction of mesoporous / microporous structures while ensuring the integrity of the particle structure, and at the same time, enable the particles to have a suitable specific surface area.

[0015] 3. In this invention, the aluminosilicate additive is defined as having a mesoporous or microporous structure with a specific surface area of ​​20 m² / g-300 m² / g. The mesoporous or microporous structure increases the surface area of ​​the aluminosilicate additive, which facilitates electrolyte wetting when the additive comes into contact with the electrolyte, allowing it to better exert its physical adsorption or buffering effect against volume changes. Abundant pores provide capillary channels for the electrolyte, ensuring that the electrolyte can quickly and fully wet the electrode interior, reducing polarization and dead zones caused by insufficient wetting, thus improving the battery's rate performance. The electrolyte filling the pores can serve as a rapid transport path for lithium ions, shortening the distance from the electrolyte bulk to the surface of the active material and reducing liquid phase transport impedance. The pore space provides a "buffer zone" for the volume expansion of the active material (especially the silicon anode), allowing some stress to be released into the pores, further enhancing the mitigation effect against volume changes.

[0016] 4. This invention also provides a solution-gel synthesis method for aluminosilicate additives, which starts from molecular or nanoscale precursors and the reaction proceeds uniformly in the liquid phase. Therefore, the solution-gel synthesis method is the easiest way to obtain a completely amorphous product with highly uniform chemical composition and highly disordered network structure. Simultaneously, by controlling the drying process, such as supercritical drying or freeze-drying, materials with high specific surface area and controllable pore structure can be prepared.

[0017] 5. This invention further defines the step of drying the washed gel. The purpose of heat treatment is to remove organic residues, stabilize the network structure, and regulate surface properties. If the calcination temperature is too low, organic residues will remain, affecting the electrochemical performance of the additive; if the temperature is too high, it will cause the amorphous network in the additive to transform into a crystalline state, completely losing the amorphous properties and stress buffering capacity required by this invention. Therefore, a heat treatment temperature range of 300°C-800°C is used to find the optimal balance between removing impurities and maintaining the amorphous structure.

[0018] 6. This invention also provides a hydrothermal synthesis method for aluminosilicate additives. Under high-temperature and high-pressure hydrothermal conditions, the mobility of atoms or ions is enhanced, which is beneficial for forming products with a denser structure and higher local order. By precisely controlling parameters such as reaction temperature and time, the amorphous network structure of the product can be controlled. For example, under relatively mild conditions, a completely amorphous product can be obtained; while at slightly higher temperatures or longer reaction times, a small amount of microcrystals can be induced on the amorphous matrix, thereby obtaining a partially amorphous product. Therefore, the hydrothermal synthesis method provides a flexible and controllable technical approach for preparing composite structures that combine the flexibility of amorphous structures and the stability of microcrystalline structures, and the products all fall within the amorphous or partially amorphous range required by this invention.

[0019] 7. The present invention also provides a lithium battery, the lithium battery comprising electrodes and a solid electrolyte, the electrodes comprising a positive electrode and a negative electrode, and at least one of the electrodes, the positive electrode, the negative electrode, and the solid electrolyte comprising the aluminosilicate additive described above. Coating this aluminosilicate additive onto the surface of a high-voltage positive electrode material can suppress interfacial side reactions between the positive electrode and the electrolyte, reduce transition metal dissolution, and improve the high-temperature cycle performance and high-voltage stability of the battery. Adding this aluminosilicate additive as a filler to a polymer electrolyte or composite electrolyte can improve the ionic conductivity, mechanical strength, and interfacial stability with the lithium metal negative electrode of the electrolyte.

[0020] 8. The present invention also provides an electronic device comprising a lithium battery as described above. This is due to the addition of an aluminosilicate additive to the lithium battery. This aluminosilicate additive contains a certain proportion of sodium and potassium, which can stabilize the structure, regulate the interface, and enhance lithium-ion transport. Firstly, in the aluminosilicate structure, sodium and potassium electrostatically stabilize the entire network structure. More importantly, the addition of sodium and potassium reduces the polymerization degree of the aluminosilicate network and affects its amorphous properties. Secondly, the surface of the additive exhibits unique Lewis acid-base sites. These sites can generate stronger chemical interactions with functional groups on the surface of the electrode active material or polar groups of the binder, enabling them to achieve good physical wetting and / or interfacial chemical interactions with the surface of lithium battery electrode active material particles, conductive agents, binders, or solid electrolyte matrix, thereby improving interfacial compatibility. Thirdly, when Na… + and K + It will affect the surrounding Li + The transport pathways and dynamics of lithium ions provide the possibility for regulating lithium-ion behavior. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a structural diagram of an aluminosilicate additive provided in the first embodiment of the present invention.

[0023] Figure 2 This is an XRD characterization of the amorphous or partially amorphous structure of an aluminosilicate additive provided in the first embodiment of the present invention.

[0024] Figure 3 This is a flowchart illustrating the solution-gel synthesis method of an aluminosilicate additive provided in the second embodiment of the present invention.

[0025] Figure 4 This is a flowchart illustrating the hydrothermal synthesis method of an aluminosilicate additive provided in the third embodiment of the present invention.

[0026] Figure 5 This is a schematic diagram of the structure of an aluminosilicate additive-coated active material particles provided in the first embodiment of the present invention.

[0027] Figure 6 This is a schematic diagram of an aluminosilicate additive as an electrode slurry filler provided in the first embodiment of the present invention.

[0028] Figure 7 This is a simplified illustration of the electronic device provided in the fourth embodiment of the present invention.

[0029] Explanation of reference numerals in the attached diagram: 1. Tetravalent silicon ions; 2. Trivalent aluminum ions; 3. Divalent oxygen ions; 4. Potassium ions; 5. Sodium ions; 6. Active material particles; 7. Aluminosilicate additive coating layer; 21. Active material particles; 22. Conductive agent; 23. Binder; 24. Aluminosilicate additive; 300, lithium battery; 400. Electronic devices. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0031] In the embodiments provided by this invention, it should be understood that "B corresponding to A" means that B is associated with A, and B can be determined based on A. However, it should also be understood that determining B based on A does not mean determining B solely based on A; B can also be determined based on A and / or other information.

[0032] It should be understood that the phrase "one embodiment" or "an embodiment" throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of the invention. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Those skilled in the art should also recognize that the embodiments described in the specification are optional embodiments, and the actions and modules involved are not necessarily essential to the invention.

[0033] In various embodiments of the present invention, it should be understood that the sequence number of each process does not necessarily imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0034] The flowcharts and block diagrams in the accompanying drawings illustrate methods and possible architectures, functions, and operations according to various embodiments of this application. In this regard, each block in the flowchart or block diagram may represent part of a step. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, or they may sometimes be executed in reverse order, depending on the functions involved.

[0035] Please see Figure 1 , Figure 1 This is a schematic diagram of the microstructure of an aluminosilicate additive provided in the first embodiment of the present invention. It includes an aluminosilicate network framework formed by covalently linked tetravalent silicon ions 1, trivalent aluminum ions 2, and divalent oxygen ions 3. The framework is a three-dimensional disordered network, with sodium ions 5 and potassium ions 4 distributed as charge-compensating cations in the micropores of the network structure. The molar ratio of sodium to potassium is 0.1:1 to 10:1, and the molar ratio of silicon to aluminum is 1:1 to 20:1. Specifically, the molar ratio of sodium to potassium can be, but is not limited to, 0.1:1 to 10:1, 0.5:1 to 8:1, or 3:1 to 6:1.

[0036] Understandably, the aluminosilicate additive of the present invention uses [SiO4] and [AlO4] tetrahedra as basic structural units. These tetrahedra are randomly connected in a three-dimensional, long-range disordered manner through shared "oxygen bridges," forming a continuous amorphous aluminosilicate network structure. Unlike crystalline materials with regular channels, the random stacking of tetrahedral units naturally forms micropores or network voids of irregular size and shape within this amorphous network. Here, an "oxygen bridge" refers to a shared oxygen atom connecting two adjacent tetrahedral units; it is the fundamental chemical bond that constructs the entire continuous, disordered network framework.

[0037] Understandably, in aluminosilicate additives, the molar ratio of silicon to aluminum can be adjusted within a wide range, such as between 1:1 and 20:1.

[0038] Specifically, the molar ratio of silicon to aluminum can be, but is not limited to, 1:1 to 20:1, 10:1 to 15:1, or 12:1 to 14:1.

[0039] Understandably, a silicon atom (Si) 4＋) by an aluminum atom (Al 3+ When replaced by [AlO4], it forms a [AlO4] molecule. － The tetrahedral unit carries a net negative charge of one unit compared to the electrically neutral [SiO4] tetrahedron. A lower Si to Al molar ratio, i.e., a relatively higher aluminum content, leads to an increase in the negative charge density within the additive framework. Electrode materials, such as LiCoO2 for the positive electrode and graphite for the negative electrode, often carry a trace positive charge on their surfaces. Lithium salts in the electrolyte, such as LiPF6, will dissociate into Li. ＋ Aluminosilicates with high negative charge density can be more tightly adsorbed onto the electrode surface through electrostatic attraction, forming a stable interface layer. [AlO4] － O in － This is a negatively charged site, which can react with active components in the electrolyte, such as the hydroxyl groups of the carbonate solvent, Li... ＋ Coordination bonds or hydrogen bonds are formed, further strengthening the interfacial bonding. A lower Si to Al molar ratio enhances the chemical affinity and physical bonding between aluminosilicate additives and electrode materials and electrolyte components, thereby promoting the formation of a more stable and compatible interface.

[0040] Understandably, a higher Si to Al molar ratio, i.e., a relatively higher silicon content, implies a higher concentration of [SiO4] in the aluminosilicate framework. － The higher the proportion of tetrahedra, the better [AlO4] content. - The lower the proportion of tetrahedra, the better. (This refers to the relationship between adjacent [SiO4] atoms.) － Tetrahedrons are tightly connected in three dimensions through high-bond-energy Si-O-Si bridging bonds. The high proportion of Si-O-Si bridging bonds in the network framework significantly enhances its overall rigidity and resistance to deformation, making it less prone to breakage due to external forces or volume changes. This results in a chemically inert and structurally more robust silicate network. This enhanced mechanical integrity provides crucial structural support for the electrodes, effectively mitigating stress caused by material volume changes during electrochemical cycling, thereby contributing to the stability and durability of battery performance.

[0041] Understandably, in the aluminosilicate of the present invention, sodium ions Na + With potassium ions K + As a cavity and / or interlayer structure of a charge-compensating cation-embedded aluminosilicate network structure, wherein the molar ratio of sodium to potassium is from 0.1:1 to 10:1.

[0042] Understandably, a silicon atom (Si) 4+ ) by an aluminum atom (Al 3+ When replaced by [AlO4], it forms a [AlO4] molecule. -The tetrahedral unit carries a net negative charge of one unit compared to the electrically neutral [SiO4] tetrahedron. To maintain the overall electrical neutrality of the material, a positively charged cation is required for charge compensation. Na + and K + The entire aluminosilicate network structure is electrostatically stabilized by balancing these negative charges by occupying the cavities or channels in the framework.

[0043] Understandably, Na + and K + The presence of these bonds will break some of the continuous bridging oxygen bonds (-Si-O-Si-) in the network structure, forming non-bridging oxygen bonds (-Si-O-). - -M + (M=Na,K). Non-bridging oxygen bonds reduce the cohesion of the network, allowing the entire three-dimensional disordered network to possess better flexibility and stress buffering capabilities while maintaining a certain degree of rigidity.

[0044] Understandably, aluminum atoms (Al) 3+ ) replace silicon atoms (Si 4+ After that, negatively charged [AlO4] will be formed. - The tetrahedral unit cells result in an overall negatively charged additive framework. To maintain the overall charge neutrality of the material, positively charged Na ions must be introduced. + and K + This neutralizes the negative charges. Positively charged Na... + and K + It will combine with [AlO4] - Oxygen atom in tetrahedral unit 2－ They are firmly bonded together by strong electrostatic attraction to form Na + / K + ionic bonds. Na + / K + Because it carries a positive charge, it can attract other negatively charged groups or groups with high electron cloud density (such as functional groups on the electrode surface or polar groups in the binder), and can serve as Lewis acid sites; the oxygen atom O 2－ Negatively charged, these sites can donate electrons to other electron-deficient groups, serving as Lewis basic sites. Lewis acid-base sites are specific chemically active centers on or within the material surface that possess electron pair accepting / donating capabilities. These acid-base sites can generate stronger chemical interactions (such as acid-base interactions and hydrogen bonds) with functional groups on the surface of the electrode active material or polar groups in the binder, enabling them to achieve good interfacial chemical interactions with the surface of lithium battery electrode active material particles, conductive agents, binders, or solid electrolyte matrix. This is the microscopic source of the "adhesive" property of this invention, thereby improving interfacial compatibility.

[0045] Understandably, when Na+ and K + When coexisting within an aluminosilicate network, Na induces a significant "mixed alkali effect," thereby greatly enhancing the structural stability of the additive itself. The principle behind this lies in Na... + (Ionic radius approximately 102 pm) and K + (Ionic radii approximately 138 pm) exhibit significant differences in size and electric field strength, causing them to tend to occupy microscopic pore sites of varying sizes and energies within the network. This disordered cation substructure, formed by the co-occupancy of two alkali metal ions and characterized by uneven energy distribution, significantly increases the activation barrier for ion migration, thereby substantially inhibiting Na+ migration. + and K + Its own mobility. Therefore, Na + and K + Firmly bound within the network framework, it is not prone to dissolution or migration even during electrochemical cycling, ensuring the high stability of the additive's chemical composition and structure.

[0046] Furthermore, this Na fixed by the "mixed base effect" + and K + And the local electrostatic field it generates can affect the surrounding Li + The transport pathways and kinetics of Li are favorablely regulated. This fixed alkali metal ion network alters the transport pathways and kinetics of Li. + The potential distribution and diffusion environment near the interface may help guide Li + More uniform deposition, or Li at the interface + Transport plays an optimizing role, and can be customized to improve specific electrochemical performance of batteries (such as suppressing dendrites and improving rate performance) by adjusting the ratio of Na to K.

[0047] The aluminosilicate additive of this invention also indirectly promotes overall lithium-ion transport by optimizing the physical and chemical environment of the electrode. On one hand, its unique surface chemistry can induce the electrolyte to form a thinner, more chemically stable, and inorganic-rich solid electrolyte interphase (SEI) or cathode electrolyte interphase (CEI) film on its surface. Compared to the interphase film formed directly on the surface of the active material, this high-quality interphase film exhibits higher Li-ion transport. + The improved conductivity and lower charge transfer resistance enhance interfacial kinetics. Furthermore, as previously mentioned, this additive effectively inhibits the pulverization of active materials and the accumulation of byproducts during cycling through its "binding" and physical support properties, preventing clogging of electrode pores and ensuring continuous and effective electrolyte wetting of the entire electrode, thus maintaining the Li... + The transport channels in the liquid phase are unobstructed.

[0048] Please see Figure 2 , Figure 2 This is a schematic diagram of the X-ray diffraction (XRD) pattern of the aluminosilicate additive provided in the first embodiment of the present invention. The solid line illustrates the typical characteristics of the amorphous structure, namely a broad, diffuse peak within the 2θ angle range of 20°-30°, without any obvious sharp crystalline phase diffraction peaks. The dashed line illustrates some characteristics of the amorphous structure, namely several sharp crystalline phase diffraction peaks superimposed on the background of the diffuse peaks.

[0049] The aluminosilicate additives are amorphous or partially amorphous. Amorphous state is a structural state of matter, characterized by the absence of long-term, regular periodicity in the arrangement of atoms or molecules, unlike crystals which have a fixed lattice structure. Partially amorphous state refers to a mixed structural state in a material where amorphous and crystalline regions coexist. It is neither a completely disordered pure amorphous state nor a purely crystalline state with perfectly regular atomic arrangements, but rather a coexistence of crystalline and amorphous phases.

[0050] Understandably, the amorphous network structure of the additive in this invention endows it with unique mechanical flexibility, enabling it to effectively mitigate volume changes in the active material when used as a coating layer. Unlike crystalline materials with rigid lattices, the amorphous network lacks long-range order and tight periodic stacking, resulting in more free volume and space for atomic rearrangement. Therefore, when the internal active material (such as a silicon anode) undergoes significant volume expansion, this flexible amorphous coating layer can effectively absorb and dissipate stress through its own plastic deformation, thereby maintaining its structural integrity. This stress buffering mechanism not only continuously protects the active material from electrolyte corrosion but also utilizes its "gluing" properties to bind potentially pulverized particles in situ, ensuring continuous electrical contact between particles and between particles and the conductive network.

[0051] Optionally, the particle size of the aluminosilicate additive is 50nm-500nm. Among them, particle size is a core physical parameter describing the size of particles in dispersion systems such as solid particles, liquid droplets or gas aerosols, and its value directly affects the physical, chemical and application properties of the particles.

[0052] Specifically, the particle size of the aluminosilicate additive can be, but is not limited to, 50nm-500nm, 100nm-450nm, or 120nm-400nm.

[0053] Understandably, the particle size of aluminosilicates is controlled to be between 50 nm and 500 nm. On the one hand, this particle size range avoids the problem that nanoscale particles smaller than 50 nm are prone to agglomeration due to their high surface energy, requiring the addition of a large amount of dispersant to maintain stability. At the same time, it avoids the drawbacks of micron-sized particles larger than 500 nm, which are prone to sedimentation and stratification and are difficult to disperse uniformly. On the other hand, a particle size of 50 nm to 500 nm can provide a reasonable spatial framework for the subsequent construction of mesoporous / microporous structures while ensuring the integrity of the particle structure, and at the same time, it enables the particles to have a moderate specific surface area.

[0054] Optionally, the aluminosilicate additive has a mesoporous or microporous structure with a specific surface area of ​​20 m² / g to 300 m² / g. Micropores refer to pore structures with a diameter less than 2 nm; mesopores refer to pore structures with a diameter between 2 nm and 50 nm; specific surface area is a core physical quantity that measures the total surface area per unit mass or unit volume of material.

[0055] In a preferred embodiment of the present invention, the specific surface area of ​​the aluminosilicate additive is from 150 m² / g to 200 m² / g. For example, the specific surface area of ​​the additive prepared by the sol-gel method can be about 180 m² / g. However, those skilled in the art will understand that, depending on different preparation methods (such as hydrothermal synthesis) or application requirements, the specific surface area of ​​the additive can be effectively controlled within the range of 20 m² / g to 300 m² / g, and these controls all fall within the protection scope of the present invention.

[0056] Understandably, the mesoporous or microporous structure increases the surface area of ​​the aluminosilicate additive. When this additive comes into contact with the electrolyte, it facilitates electrolyte wetting. The abundant pores provide capillary channels for the electrolyte, ensuring that the electrolyte can quickly and fully wet the electrode interior, reducing polarization and dead zones caused by insufficient wetting, and thus improving the battery's rate performance. The electrolyte filling the pores can serve as a rapid transport path for lithium ions, shortening the distance from the electrolyte bulk to the surface of the active material and reducing liquid phase transport impedance. The pore space provides a "buffer zone" for the volume expansion of the active material (especially the silicon anode), allowing some stress to be released into the pores, further enhancing the mitigation effect on volume changes.

[0057] Please see Figure 3 The diagram illustrates the steps of a solution-gel synthesis method for an aluminosilicate additive provided in the second embodiment of the present invention, specifically including the following steps: Step S11: Hydrolyze the silicon source under acid catalysis to obtain a silica sol; dissolve the aluminum source, sodium source, and potassium source in a solvent to obtain a salt solution, wherein the content of the silicon source and the aluminum source are in a certain proportion, and the content of the sodium source and the potassium source are in a certain proportion. Step S12: The salt solution is added dropwise to the silica sol, and the pH is adjusted to 7-9 to form a gel; and Step S13: After aging the gel, wash and dry it to obtain the aluminosilicate additive as described above.

[0058] Optionally, in step S11, the molar ratio of the silicon source to the aluminum source is 5:1, and the molar ratio of the sodium source to the potassium source is 3:1.

[0059] Optionally, in step S11, the silicon source is hydrolyzed under acid catalysis for 1-2 hours.

[0060] Optionally, in step S12, the salt solution is added dropwise to the silica sol, and the dropping rate can be controlled at 1-10 mL / min.

[0061] Optionally, in step S13, the gel is aged at 60°C for 24 hours. Aging refers to the process of placing a chemical reaction system under specific conditions for a period of time, allowing the system to transition from a "thermodynamically non-equilibrium state" to a "more stable equilibrium state" through slow physical or chemical changes. Its core purpose is to optimize the structure, purity, or properties of the product, and it is a key auxiliary step in chemical preparation or analysis to improve product quality.

[0062] Optionally, in step S13, washing can be performed by repeatedly centrifuging the gel with deionized water and ethanol to remove impurity ions.

[0063] Optionally, in step S13, the drying process can be supercritical drying or freeze drying.

[0064] Understandably, conventional oven drying can lead to pore structure collapse and particle agglomeration caused by capillary forces, reducing specific surface area and dispersibility. In contrast, freeze drying or supercritical drying can better maintain the original network structure and high specific surface area of ​​aluminosilicate additives.

[0065] Optionally, in step S13, the drying process further includes the following steps: Step S131: The washed gel is dried in an oven at 80℃-120℃ to obtain the dried product; and, Step S132: The dried product is heat-treated in air or an inert atmosphere at 300℃-800℃ for 2 hours.

[0066] Understandably, in step S132, the purpose of heat treatment is to remove organic residues, stabilize the network structure, and regulate surface properties. If the heat treatment temperature is too low, organic residues will remain, affecting electrochemical performance; if the heat treatment temperature is too high, the aluminosilicate will undergo a transformation from an amorphous to a crystalline state, completely losing the amorphous properties and stress-buffering capacity required by this invention. Therefore, this invention employs a mild heat treatment temperature range of 300℃-800℃, aiming to find the optimal balance between impurity removal and maintaining the amorphous structure.

[0067] Specifically, the heat treatment temperature range can be, but is not limited to, 300℃-800℃, 400℃-700℃, or 450℃-600℃.

[0068] Understandably, the solution-gel synthesis method for aluminosilicate additives starts from molecular or nanoscale precursors, with the reaction proceeding uniformly in the liquid phase. Therefore, this method most readily yields fully amorphous products with highly homogeneous chemical composition and highly disordered network structures. Furthermore, by controlling the drying process, such as supercritical drying or freeze-drying, materials with high specific surface area and controllable pore structures can be prepared.

[0069] Please see Figure 4 The diagram shows the steps of a hydrothermal synthesis method for an aluminosilicate additive provided in the third embodiment of the present invention, specifically including the following steps: Step S21: Dissolve a certain proportion of silicon source, aluminum source, sodium source and potassium source in a solvent to form a precursor mixture; Step S22: The precursor mixture is subjected to a hydrothermal reaction at 120℃-250℃ to obtain a solid-liquid product; after cooling the solid-liquid product, it is filtered to obtain a solid product; and Step S23: The solid product is washed and dried to obtain the aluminosilicate additive as described above.

[0070] Optionally, in step S21, the silicon source is a sodium silicate solution; the aluminum source is sodium aluminate; the sodium source is a sodium silicate solution, sodium aluminate, and sodium hydroxide; and the potassium source is potassium hydroxide.

[0071] Understandably, sodium hydroxide serves not only as a sodium source but also as a pH adjuster.

[0072] Optionally, in step S21, the solvent can be deionized water.

[0073] Optionally, in step S21, the molar ratio of silicon source to aluminum source is 2:1, and the molar ratio of sodium source to potassium source is 4:1.

[0074] Optionally, in step S22, a hydrothermal reaction is carried out, in which the mixture is transferred to a hydrothermal reactor and reacted at 180°C-220°C for 12-48 hours.

[0075] Specifically, the temperature of the hydrothermal reaction can be, but is not limited to, 180°C-220°C, 190°C-210°C, or 195°C-200°C. The time of the hydrothermal reaction can be, but is not limited to, 12h-48h, 18h-40h, or 30h-35h.

[0076] Optionally, in step S23, the solid product is dried, which may be done at 60°C-150°C.

[0077] Understandably, in step S23, the purpose of washing is to remove residual soluble precursor salts and reaction byproducts. If washing is insufficient, impurity ions remain in the aluminosilicate additive, which, after entering the battery, can become catalysts for electrochemical side reactions, or precipitate on the electrode surface, blocking ion channels and leading to rapid deterioration of battery performance and reduced safety.

[0078] Understandably, in step S24, the purpose of drying is to remove the solvent from the physical adsorption and pores.

[0079] Understandably, the aluminosilicate additives described in this invention can also be prepared by hydrothermal synthesis. Under high temperature and high pressure hydrothermal conditions, the mobility of atoms or ions is enhanced, which is conducive to the formation of products with a denser structure and higher local order. By precisely controlling parameters such as reaction temperature and time, the amorphous network structure of the product can be controlled. For example, under relatively mild conditions, a completely amorphous product can be obtained; while at slightly higher temperatures or longer reaction times, a small amount of microcrystals can be induced to form on the amorphous matrix, thereby obtaining a partially amorphous product. Therefore, hydrothermal synthesis provides us with a flexible and controllable technical approach to prepare composite structures that combine the flexibility of amorphous structures and the stability of microcrystalline structures, and the products all fall within the amorphous or partially amorphous range required by this invention.

[0080] Please see Figure 5 The first embodiment of the present invention provides a schematic diagram of an active material particle coated with an aluminosilicate additive. The diagram depicts an active material particle 6 coated with a thin and uniform aluminosilicate additive coating layer 7. This aluminosilicate additive coating layer 7 effectively isolates the active material particle 6 from direct contact with the electrolyte, suppresses interfacial side reactions, and can alleviate the volume change of the active material during charging and discharging to a certain extent, thereby improving the structural stability of the electrode and the cycle life of the battery.

[0081] Optionally, the aluminosilicate additive nanopowder prepared according to this invention is ultrasonically dispersed in a suitable solvent to form a stable suspension. Then, the electrode active material powder is added to this suspension, and the mixture is continuously stirred or ultrasonicated to ensure that the additive particles are uniformly adsorbed onto the surface of the active material. Finally, the solvent is removed by evaporation, and possibly a heat treatment is performed to enhance the bonding force between the aluminosilicate additive coating layer and the active material particles, forming a core-shell structured composite material. The solvent includes an ethanol / water mixture.

[0082] Understandably, aluminosilicate additives can suppress interfacial side reactions by coating active material particles. The aluminosilicate additives provide a stable and chemically inert aluminosilicate network framework. This framework forms a physical coating layer that effectively isolates the highly active electrode surface from the corrosive organic electrolyte. This directly prevents excessive oxidation / reduction decomposition of the electrolyte, as well as the corrosion of the cathode material by HF and the dissolution of transition metal ions.

[0083] Understandably, aluminosilicate additives coating active material particles can mitigate electrode volume changes. Unlike rigid crystalline materials, amorphous networks lack a fixed long-range ordered structure; their atomic arrangement is relatively loose, providing ample microscopic space for deformation. When the internal active material undergoes significant volume expansion, this flexible amorphous coating layer acts like an elastic buffer, absorbing and releasing stress through the network's own deformation, rather than shattering directly like a rigid coating. This maintains the integrity of the coating layer, continuously protecting the active material.

[0084] Please see Figure 6 The first embodiment of the present invention provides a schematic diagram of an aluminosilicate additive as an electrode slurry filler, wherein the active material particles 21, the conductive agent 22 and the binder 23 together constitute the electrode structure.

[0085] Understandably, the aluminosilicate additive 24 of the present invention is dispersed and filled in the form of irregular particles between the active material particles 21, the conductive agent 22, and the binder 23, thereby enhancing the physical connection. In the electrode, the active material particles 21, the conductive agent 22, and the binder 23 constitute a porous composite structure. As a nanoscale filler, the aluminosilicate additive 24 of the present invention can fill the micron-sized gaps between the active material particles 21, making the active material particles 21 more tightly connected. During charge-discharge cycles, even if the binder 23 degrades due to aging, these rigid inorganic fillers can still provide a stable three-dimensional physical support framework, limiting the relative displacement and detachment of the active particles, thereby enhancing the structural integrity and fatigue resistance of the entire electrode.

[0086] Understandably, the aluminosilicate additive 24 of the present invention is dispersed and filled in the form of irregular particles between the active material particles 21, the conductive agent 22, and the binder 23, which can improve interfacial compatibility. The surface of this additive is rich in Lewis acid-base sites and polarity due to the introduction of Al and the presence of non-bridging oxygen bonds. This allows it to form chemical interactions stronger than van der Waals forces, such as hydrogen bonds and acid-base coordination, with the equally polar polymeric binder. This strong interaction significantly improves the bonding strength of the "filler-binder-active material" three-phase interface, forming a stable interface and avoiding delamination and contact failure caused by interfacial incompatibility during cycling. Here, polarity refers to the characteristic that the surface of a molecule or material exhibits a partially positive charge at one end and a partially negative charge at the other due to the non-coincidence of positive and negative charge centers, enabling it to attract other polar substances through charge interactions.

[0087] Please see Figure 7 A fourth embodiment of the present invention provides an electronic device 400, which includes a lithium battery 300 as described in the present invention. The lithium battery can serve as a power source or a power source for a monitoring module in the electronic device. The number of lithium batteries can be one or more.

[0088] To achieve better control and meet safety requirements, the lithium battery can be connected to an intelligent monitoring system to enable intelligent control and real-time performance monitoring, thereby understanding the operating status of the lithium battery in the electronic device and improving the safety of lithium battery use.

[0089] The electronic device may be any one of a mobile phone, tablet, electric vehicle, or smart wearable device.

[0090] In order to better illustrate the performance of the aluminosilicate additive claimed in this invention, the present invention is further illustrated by the following experimental examples and comparative examples.

[0091] Experimental Example 1: The effect of the additive of the present invention on improving the performance of silicon-based anodes 1. Preparation of negative electrode slurry: The standard silicon-based negative electrode active material, the aluminosilicate additive prepared according to this invention (product of Experimental Example 1, Na / K=3:1, Si / Al=5:1), and the conductive agent (such as Super P) were mixed uniformly at high speed in NMP (N-methylpyrrolidone) solvent at a mass ratio of 85:5:10. Then, a binder (PVDF) was added, and stirring continued to form a uniform negative electrode slurry. The binder's solid content accounted for 10% of the total solids.

[0092] 2. Electrode Preparation and Battery Assembly: The above slurry was uniformly coated onto a copper foil current collector, vacuum dried, rolled, and then punched into circular electrode sheets. Using these electrode sheets as the working electrode, a lithium metal sheet as the counter electrode, and Celgard 2400 as the separator, CR2032 coin cells were assembled in an argon-filled glove box. The electrolyte was a 1 M LiPF6 solution dissolved in a mixed solvent of EC / DEC / DMC (volume ratio 1:1:1).

[0093] Comparative Example 1: Except for the absence of any aluminosilicate additives, the remaining steps were exactly the same as in Experimental Example 1. To maintain a constant total solid mass, the mass percentage of the active material was adjusted accordingly to 90%.

[0094] Comparative Example 2: Except for replacing the aluminosilicate additive of the present invention with an equal mass (i.e., 5% of the total solid mass) of commercially available nano-SiO2 powder (average particle size ~50nm), the other steps are exactly the same as in Experimental Example 1.

[0095] Electrochemical performance testing: After the assembled battery was left to stand at room temperature for 12 hours, the following tests were performed using a battery testing system: Cyclic performance testing: Long-cycle charge-discharge tests were conducted at 0.5C / 0.5C rates, and the capacity retention rate was recorded.

[0096] Charge transfer resistance (Rct) testing: The battery was subjected to EIS testing using an electrochemical workstation before and after 200 cycles to analyze changes in charge transfer resistance. A 5mV sinusoidal AC perturbation signal was applied at the battery's open-circuit voltage, with a test frequency range of 100 kHz to 0.01 Hz. The charge transfer resistance (Rct) was determined by equivalent circuit fitting of the obtained Nyquist plot. Table 1 - Comparison of Capacity Retention Rate

[0097] Table 1 shows that Group C of the present invention retains more than 80% of its capacity after 200 cycles, which is significantly better than Comparative Example 1 and Comparative Example 2. This indicates that the additive of the present invention can effectively stabilize the interface and buffer volume expansion, thereby significantly improving the cycle life of the battery.

[0098] Table 2 - Charge Transfer Resistance Test After Cycling

[0099] Table 2 shows that after cycling, Experimental Example 1 showed the smallest increase in charge transfer resistance, significantly lower than the two comparative examples. This strongly demonstrates that the additive of the present invention can promote the formation of a thinner, more stable interface layer with better ionic conductivity, thereby suppressing the malignant growth of impedance.

[0100] The foregoing has provided a detailed description of an aluminosilicate additive and its synthesis method, as well as a lithium battery and electronic device, disclosed in the embodiments of the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention. Any modifications, equivalent substitutions, and improvements made within the principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An aluminosilicate additive, characterized in that: The additive is an amorphous or partially amorphous aluminosilicate containing sodium and potassium ions; wherein the molar ratio of sodium to potassium in the aluminosilicate is 0.1:1 to 10:1, and the molar ratio of silicon to aluminum is 1:1 to 20:

1.

2. The aluminosilicate additive as described in claim 1, characterized in that: The particle size of the aluminosilicate additive is 50nm-500nm.

3. The aluminosilicate additive as described in claim 1, characterized in that: The aluminosilicate additive has a mesoporous or microporous structure with a specific surface area of ​​20 m² / g to 300 m² / g.

4. A solution-gel synthesis method for preparing aluminosilicate additives, characterized in that, Includes the following steps: The silicon source is hydrolyzed under acid catalysis to obtain a silica sol; the aluminum source, sodium source and potassium source are dissolved in a solvent to obtain a salt solution, wherein the contents of the silicon source and the aluminum source are in a certain proportion, and the contents of the sodium source and the potassium source are in a certain proportion. The salt solution is added dropwise to the silica sol, and the pH is adjusted to 7-9 to form a gel; and The gel is aged, washed, and dried to obtain the aluminosilicate additive as described in any one of claims 1-3.

5. The method for using aluminosilicate additives as described in claim 4, characterized in that: The drying process includes the following steps: The washed gel was dried in an oven at 80℃-120℃ to obtain the dried product; and, The dried product was heat-treated at 300℃-800℃ in air or an inert atmosphere for 2 hours.

6. A hydrothermal synthesis method for preparing aluminosilicate additives, characterized in that: A certain proportion of silicon source, aluminum source, sodium source and potassium source are dissolved in a solvent to form a precursor mixture; The precursor mixture was subjected to a hydrothermal reaction at 120°C-250°C to obtain a solid-liquid product; after cooling the solid-liquid product, it was filtered to obtain a solid product. The solid product is washed and dried to obtain the aluminosilicate additive as described in any one of claims 1-3.

7. A lithium battery, characterized in that, The lithium battery includes electrodes and a solid electrolyte. The electrodes include a positive electrode and a negative electrode. At least one of the electrodes, positive electrode, negative electrode, and solid electrolyte contains the aluminosilicate additive as described in claims 1-3. The aluminosilicate additive serves as a filler in the electrode slurry and / or serves as a coating layer for the positive and / or negative electrode active materials and / or serves as an active / inactive filler in the solid electrolyte.

8. An electronic device, characterized in that, The electronic device includes the lithium battery as described in claim 7; the electronic device is any one of a mobile phone, tablet, electric vehicle, or smart wearable device.

Images