Oxide ceramic particles coated with amination functional groups

Abstract

An oxide ceramic particle coated with anamine functional groups, wherein the particle is a plurality of composite LLZO (lithium lanthanum zirconium oxide) particles, each composite LLZO particle comprising: an LLZO particle for guiding and dispersing lithium ions through the positive electrode; a hydroxide ion layer coating the outer surface of the LLZO particle, forming a primary and secondary LLZO particle; and a dopamine layer coating the exterior of the secondary LLZO particle, thus forming the composite LLZO particle; the dopamine has hydrophobic properties, which can further protect the LLZO particle from moisture. The dopamine layer and the hydroxide ion layer contain CTAB (cetyltrimethylammonium bromide), wherein the dopamine layer is further coated with a CTAB layer.

Description

Technical Field

[0001] This work relates to electrode materials, particularly oxide ceramic particles coated with amination functional groups. Prior Technology

[0002] A battery is mainly formed by placing electrodes (positive and negative electrodes) in an electrolyte. In conventional technology, LLZO material is added to the electrodes to increase ionic conductivity. LLZO has high ionic conductivity for lithium ions. Therefore, when lithium ions pass through the electrode, the dispersed LLZO particles guide the lithium ions, dispersing their pathways. This allows for a uniform distribution of lithium ions within the electrode, preventing abnormal accumulation and side reactions within the electrode slurry.

[0003] However, during the manufacturing process of this electrode, the LLZO material is prone to side reactions with the materials in the electrode, causing the materials in the electrode slurry to deteriorate.

[0004] Based on extensive experience with battery materials, the applicant proposes a novel design: coating the LLZO material with dopamine to impart hydrophobic properties, thus making it more difficult for moisture to penetrate the LLZO material. Furthermore, carbon nanotubes and nanoscale amorphous carbon are added to the outer surface of the dopamine-coated LLZO material to encapsulate the electrode particles in the battery's electrode material, thereby improving the overall conductivity of the electrode.

[0005] Therefore, this application aims to propose a novel oxide ceramic particle coated with amination functional groups to overcome the aforementioned deficiencies in the prior art. Summary of the Invention

[0006] Therefore, the purpose of this invention is to solve the aforementioned problems in the prior art. This invention proposes an oxide ceramic particle coated with amination functional groups. A dopamine layer is coated on the outer surface of the secondary LLZO particle. Dopamine has hydrophobic properties, so coating the outer surface of the secondary LLZO particle with this dopamine layer makes it more difficult for moisture to penetrate the LLZO particle. This invention also coats the composite LLZO particle with nanoscale amorphous carbon and carbon nanotubes as conductive agents. The nanoscale amorphous carbon is in particle form, while the carbon nanotubes are in elongated form. The addition of nanoscale amorphous carbon into the gaps contributes to the overall conductivity of the structure. This invention utilizes the dopamine layer, the multiple carbon nanotubes, and the nanoscale amorphous carbon to form a multi-layered protection, thus the entire composite LLZO particle structure has enhanced lithium conductivity, achieving better battery electrode material manufacturing quality.

[0007] To achieve the above objectives, this invention proposes an oxide ceramic particle coated with amination functional groups, wherein the oxide ceramic particle coated with amination functional groups is a plurality of composite LLZO particles. The composite LLZO particles are added to an electrode of a solid-state or near-solid-state battery. The electrode includes: an electrode substrate and an electrode paste layer coated on the electrode substrate; the structure of each composite LLZO particle includes: an LLZO particle for guiding and dispersing lithium ions through the electrode, thus allowing lithium ions to present a uniform channel distribution within the electrode; a hydroxide ion layer is coated on the outer surface of the LLZO particle, forming a primary and secondary LLZO particle structure; wherein the hydroxide ion layer is composed of tris(hydroxymethyl)amine added during the manufacturing process of the composite LLZO particles, wherein the tris(hydroxymethyl)amine... Methylamine has three OH- bonds. Two of these OH- bonds are bonded to the oxidized functional groups of the LLZO particles themselves. The third OH- bond on the tris(hydroxymethyl)amine extends towards the outer surface of the LLZO particles, forming a hydroxyl ion layer. A dopamine layer coats the exterior of the secondary LLZO particles, forming a composite LLZO particle. This layer is formed through a copolymerization reaction between dopamine molecules. The OH- bonds of the dopamine react with the third OH- bond in the hydroxyl ion layer through a dehydration polymerization reaction, allowing the dopamine to combine with the secondary LLZO particles, thus forming the composite LLZO particle. The dopamine has hydrophobic properties, further protecting the LLZO particles from moisture. A CTAB layer, a surfactant, is also coated on the exterior of the dopamine layer. The dopamine layer and the hydroxide ion layer contain CTAB; the CTAB molecules exert an attractive force on molecules with opposite polarities in the dopamine layer and the hydroxide ion layer due to their molecular polarity. The weight ratio of "the total weight of the CTAB mixed in the dopamine layer and the hydroxide ion layer, and the total weight of the CTAB in the CTAB layer" to the total weight of the dopamine in the dopamine layer is between 0.1% and 0.3%.

[0008] The addition of CTAB can improve the dispersion of the LLZO particles and prevent them from agglomerating, thus reducing the possibility of lithium fluorination between the LLZO particles and the cathode slurry.

[0009] The features and advantages of this work will be further explained in the following description; please refer to the accompanying drawings while reading. Simple Explanation of the Diagram

[0010] Figure 1 shows the structural diagram of this case.

[0011] Figure 2 shows an application example of this case.

[0012] Figure 3 shows an enlarged schematic diagram of the hydroxide ion layer structure in this case.

[0013] Figure 4 shows the structure of the three-level LLZO particles in this case.

[0014] Figure 5 shows an enlarged schematic diagram and structural diagram of the dehydration polymerization reaction in which the OH- bond of the dopamine itself forms a third OH- bond in the hydroxide ion layer.

[0015] Figure 6 shows a schematic diagram illustrating the attraction between the OH- bonds of CTAB and dopamine, and the OH- bonds of the hydroxide ion layer.

[0016] Figure 7 shows a cross-sectional view of the dopamine layer in this case, which is still covered by the CTAB layer. Implementation

[0017] The following is a detailed description of a preferred embodiment of this invention, along with its structural components, effects, and advantages, in conjunction with the accompanying drawings.

[0018] Please refer to Figures 1 to 7, which show the oxide ceramic particles coated with amination functional groups of this invention. These particles are multiple composite LLZO (lithium lanthanum zirconium oxide) particles 100, which are mainly used in the electrodes of solid-state or solid-state-like batteries, especially the positive electrode 10 of such batteries. The particle size of the composite LLZO particles 100 ranges from 50 nanometers to 200 nanometers.

[0019] The positive electrode 10 includes: a positive electrode substrate 11, which is a carrier plate for supporting the positive electrode 10; a positive electrode slurry layer 13 coated on the positive electrode substrate 11, the positive electrode slurry layer 13 including a positive electrode slurry 12 as a binder. The positive electrode slurry layer 13 further includes: the plurality of composite LLZO particles 100. The proportion of the composite LLZO particles 100 in the electrode slurry layer (especially the positive electrode slurry layer) is between 0.5 wt% and 5 wt%.

[0020] The structure of a composite LLZO particle 100 according to the present invention is described below. The composite LLZO particle 100 comprises:

[0021] The LLZO particles are 15, mainly because LLZO material has high ionic conductivity for lithium ions. Therefore, when lithium ions pass through the electrode, the multiple dispersed LLZO particles can guide and disperse the lithium ion pathways, thus allowing the lithium ions to present a uniform channel distribution inside the electrode. This avoids abnormal accumulation of lithium ions in the electrode slurry and prevents side reactions with the electrode slurry.

[0022] Because moisture is present during the manufacturing process of this electrode, and the LLZO particles are hydrophilic and therefore easily absorb moisture and produce alkaline substances, the outer layer of the LLZO particles must be covered with a protective layer to prevent the LLZO particles from absorbing moisture during the manufacturing process of this electrode.

[0023] The LLZO particles are lithium lanthanum zirconium oxide (Li7La3Zr2O12, LLZO), or are formed by lithium lanthanum zirconium oxide doped with at least one metal element (e.g., Li6.2Ga0.8La3Zr2O12, which is a gallium (Ga) doped lithium lanthanum zirconium oxide compound, or it can also be an aluminum (Al) doped or barium (Ba) doped lithium lanthanum zirconium oxide compound).

[0024] A hydroxide ion (OH-) layer 24 coats the outer surface of the LLZO particle 15, forming a primary and secondary LLZO particle 30 (as shown in Figure 3). The thickness of the hydroxide ion layer 24 is between 0.5 nanometers and 2 nanometers. The hydroxide ion layer 24 is formed by adding tris(hydroxymethyl)amine during the manufacturing process of the composite LLZO particle 100. The tris(hydroxymethyl)amine itself has three OH- bonds. Two of the OH- bonds in the tris(hydroxymethyl)amine are used to form hydrogen bonds with the oxidative functional groups on the LLZO particle 15, while the third OH- bond of the tris(hydroxymethyl)amine extends towards the outer surface of the LLZO particle 15, thereby forming the hydroxide ion layer 24 (as shown in Figure 3). Only two tris(hydroxymethyl)amine molecules are shown in the figure; this number is for illustrative purposes only and is not intended to limit the scope of this invention.

[0025] A dopamine layer 35 coats the exterior of the secondary LLZO particles 30, forming the composite LLZO particle 100 (as shown in Figure 1). Copolymerization occurs between the dopamines, thus forming the dopamine layer 35. The OH- bonds of the dopamine itself undergo a dehydration polymerization reaction with the third OH- bond of the hydroxide ion layer 24, allowing each dopamine to combine with the secondary LLZO particles 30, collectively forming the composite LLZO particle 100 (as shown in Figure 5). The thickness of the dopamine layer 35 is between 1 nanometer and 10 nanometers.

[0026] The purpose of coating the secondary LLZO particles 30 with the dopamine layer 35 is primarily because moisture is present during the manufacturing process of the electrode paste. Since the LLZO particles 15 are hydrophilic, they are easily affected by moisture, producing alkaline byproducts that compromise their lithium conductivity. Dopamine, on the other hand, is hydrophobic; therefore, coating the secondary LLZO particles 30 with the dopamine layer 35 further protects them from moisture absorption.

[0027] The purpose of applying the hydroxide ion layer 24 to coat the outer surface of the LLZO particles 15 is because hydroxide ions (OH-) are polar. Therefore, by coating the hydroxide ion layer 24, they can react with the dopamine material of the dopamine layer 35, so that the dopamine material can better adhere to the secondary LLZO particles 30.

[0028] As shown in Figures 6 and 7, the dopamine layer 35 is further coated with a CTAB (cetyltrimethylammonium bromide) layer 61, which is composed of multiple CTAB 60s. CTAB is a surfactant. Multiple CTAB 60s are also mixed within the dopamine layer 35 and the hydroxide ion layer 24.

[0029] The weight ratio of the total weight of CTAB 60 mixed in the dopamine layer 35 and the hydroxide ion layer 24 and the total weight of CTAB 61 in the dopamine layer 35 to the total weight of dopamine in the dopamine layer 35 is between 0.1% and 0.3%.

[0030] The distribution ratio of CTAB 60 in the dopamine layer 35, the hydroxide ion layer 24, and the CTAB layer 61 is a natural result of the manufacturing process. A portion of the CTAB 60 is mixed within the dopamine layer 35 and the hydroxide ion layer 24, while the remainder forms another coating layer (i.e., the CTAB layer 61) around the dopamine layer 35. The CTAB molecules exert an attractive force due to their polarity against molecules with opposite polarities in the dopamine layer 35 and the hydroxide ion layer 24.

[0031] Adding CTAB can improve the dispersion of each LLZO particle 15 and prevent agglomeration, reducing the possibility of lithium fluorination between the LLZO particles 15 and PVDF (polyvinylidene fluoride) in the positive electrode slurry. For the LLZO particles 15 to avoid agglomeration, their charge must be concentrated. During the modification process of the LLZO particles 15, locally exposed OH- bonds may form on the surface of the LLZO particles 15 (including the third OH- bond of the hydroxide ion layer 24 or the OH- bonds of the dopamine layer 35 itself). The CTAB carries a positive charge on one side and a negative charge on the other (as shown in Figure 6). The positively charged part of the CTAB can attract the exposed OH- bonds of the composite LLZO particles 100 without changing the overall charge. This not only improves the integrity of the surface coating but also prevents dopamine agglomeration, and the composite LLZO particles 100 are not exposed, thus avoiding alkalinity.

[0032] During the manufacturing process, the third OH- bond of the hydroxide ion layer 24 may not all undergo dehydration polymerization with the OH- bonds of dopamine itself, so there are still exposed OH- bonds. The CTAB can attract the exposed OH- bonds, or the CTAB can attract the OH- bonds of dopamine itself, thus forming a layered protective structure with more complete overall coverage.

[0033] This case also includes:

[0034] Multiple carbon nanotubes 42 (CNTs) and multiple nano-sized amorphous carbon 45 are coated onto each composite LLZO particle 100 to form a tertiary LLZO particle 50 (as shown in Figure 4). The size of the carbon nanotubes 42 ranges from 200 nm to 500 nm, and the size of the nano-sized amorphous carbon 45 ranges from 10 nm to 40 nm. The nano-sized amorphous carbon 45 may be, for example, a super P conductive agent.

[0035] In each of the three-level LLZO particles 50, the weight ratio of the total weight of the corresponding "multiple carbon nanotubes 42 and the nano-level amorphous carbon 45" to the total weight of the LLZO particle 15 (i.e., the single LLZO particle 15) is 0.2~2:99.8~98.

[0036] The nanoscale amorphous carbon 45, like the carbon nanotube 42, serves as a conductive agent. Because the nanoscale amorphous carbon 45 is in particle form, while the carbon nanotube 42 is in elongated form, gaps are formed between the crisscrossing carbon nanotubes 42. These gaps cannot conduct current. Therefore, adding the nanoscale amorphous carbon 45 into these gaps allows charge to be conducted to the next carbon nanotube 42 through the bridging of the nanoscale amorphous carbon 45, thus further increasing current transfer.

[0037] The advantage of this carbon nanotube 42 is that lithium ions can be easily stabilized between the nanotubes. Therefore, the electrode paste in this case can stabilize a large number of lithium ions, thus improving the overall lithium ion conductivity. Furthermore, electrons can be easily fixed between the carbon nanotubes 42, thereby improving the overall lithium ion conductivity. Moreover, because the ion conductivity is very high, it facilitates rapid charging and discharging of the entire battery, and also reduces the amount of cobalt used, thus lowering the overall production cost.

[0038] In this invention, a dopamine layer is coated on the outer surface of the secondary LLZO particles. This dopamine layer has hydrophobic properties, thus making it more difficult for moisture to penetrate the LLZO particles. Furthermore, nanoscale amorphous carbon and carbon nanotubes are coated on the composite LLZO particles as conductive aids. The nanoscale amorphous carbon is in particle form, while the carbon nanotubes are in elongated form. The inclusion of nanoscale amorphous carbon in the gaps contributes to the overall conductivity of the structure. This invention utilizes the dopamine layer, multiple carbon nanotubes (CTAB), and nanoscale amorphous carbon to form a multi-layered protective layer. Therefore, the entire composite LLZO particle structure has enhanced lithium conductivity and avoids reactions with materials in the electrode slurry during electrode manufacturing, achieving better battery electrode material manufacturing quality.

[0039] In conclusion, the human-centered and considerate design of this case is highly in line with actual needs. Its specific improvements over existing deficiencies represent a significant breakthrough compared to prior art, offering genuine functional enhancements that are not easily achieved. Furthermore, since this case has not been publicly disclosed or revealed in domestic or international literature or markets, it complies with patent law requirements.

[0040] The above detailed description is a specific description of one feasible embodiment of the present invention. However, the embodiment is not intended to limit the patent scope of the present invention. All equivalent implementations or modifications that do not depart from the spirit of the present invention should be included in the patent scope of this case.

[0041] 10: Positive electrode

[0042] 11: Positive electrode substrate

[0043] 12: Positive electrode slurry

[0044] 13: Positive electrode slurry layer

[0045] 15: LLZO particles

[0046] 24: Hydroxide Ion Layer

[0047] 30: Secondary LLZO particles

[0048] 35: Dopamine layer

[0049] 42: Carbon nanotubes

[0050] 45: Nanoscale amorphous carbon

[0051] 50: Grade III LLZO particles

[0052] 61: CTAB layer

[0053] 60:CTAB

[0054] 100: Composite LLZO particles

Claims

1. An oxide ceramic particle coated with an amination functional group, wherein the oxide ceramic particle coated with an amination functional group is a plurality of composite LLZO particles, the composite LLZO particles being added to an electrode of a solid-state or near-solid-state battery, the electrode comprising: an electrode substrate and an electrode paste layer coated on the electrode substrate; the structure of each composite LLZO particle comprising: an LLZO particle for guiding and dispersing lithium ions through the electrode; thereby enabling lithium ions to present a uniform channel distribution inside the electrode; a hydroxide ion layer coating the outer surface of the LLZO particles, forming a primary and secondary LLZO particle; wherein the hydroxide ion layer is formed by adding tris(hydroxymethyl)amine during the manufacturing process of the composite LLZO particles, wherein the tris(hydroxymethyl)amine has three OH- bonds, and two of the OH- bonds of the tris(hydroxymethyl)amine are bonded to the oxidized functional groups of the LLZO particles themselves; and the tris(hydroxymethyl)amine... The third OH- bond on the methylamine extends towards the outer surface of the LLZO particle, thereby forming the hydroxide ion layer; a dopamine layer coats the exterior of the secondary LLZO particle, forming the composite LLZO particle; the dopamine layer is formed due to the copolymerization reaction between dopamines; the OH- bonds of the dopamine itself undergo a dehydration polymerization reaction with the third OH- bond of the hydroxide ion layer, allowing the dopamine to combine with the secondary LLZO particle to form the composite LLZO particle; the dopamine has hydrophobic properties, which can further protect the LLZO particle from moisture; the particle size of the LLZO particle is between 50 nm and 200 nm; the proportion of the composite LLZO particle in the electrode paste layer is between 0.5 wt% and 5 wt%; the thickness of the hydroxide ion layer is between 0.5 nm and 2 nm; and the thickness of the dopamine layer is between 1 nm and 10 nm.

2. The oxide ceramic particles coated with amination functional groups as described in claim 1, wherein the dopamine layer is further coated with a CTAB layer, the CTAB being a surfactant; wherein the dopamine layer and the hydroxide ion layer contain a plurality of CTABs; each CTAB will exert an attractive force on molecules with opposite polarities in the dopamine layer and the hydroxide ion layer by utilizing the polarity of its molecules; wherein the weight ratio of "the total weight of the CTABs mixed in the dopamine layer and the hydroxide ion layer and the total weight of the CTABs in the CTAB layer" to the total weight of the dopamine in the dopamine layer is between 0.1% and 0.3%; wherein the addition of CTAB can improve the dispersibility of each LLZO particle without forming agglomerates, reducing the possibility of lithium fluorination of the LLZO particles with the positive electrode slurry.

3. The oxide ceramic particles coated with amination functional groups as described in claim 1, wherein the composite LLZO particles are used in a positive electrode.

4. The oxide ceramic particles coated with amination functional groups as described in any one of claims 1 or 2 further comprises: a plurality of carbon nanotubes and a plurality of nano-grade amorphous carbon coated on the outer surface of the composite LLZO particles to form a tertiary LLZO particle; wherein the size of the carbon nanotubes is between 200 nanometers and 500 nanometers; wherein the size of the nano-grade amorphous carbon is between 10 nanometers and 40 nanometers; wherein in each of the tertiary LLZO particles, the weight ratio of the corresponding "total weight of the plurality of carbon nanotubes and the nano-grade amorphous carbon" to the total weight of the LLZO particles is 0.2~2:99.8~98.

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