Positive electrode plate containing phosphate ceramic particles coated with a carbon layer

Abstract

A positive electrode plate is provided that includes phosphate-based ceramic particles coated with a carbon layer. [Solution] A positive electrode plate (11) containing composite ceramic particles is used in a solid or semi-solid battery. The solid or semi-solid battery includes a positive electrode (10), a negative electrode (40), and a dielectric thin film layer (45) attached between the positive and negative electrodes. The positive electrode includes a positive electrode plate. The positive electrode plate includes a positive electrode substrate (12) for supporting the positive electrode material and a positive electrode slurry layer (13) coated on the positive electrode substrate and composed of a positive electrode slurry. The positive electrode slurry includes a plurality of positive electrode particles (15) for storing or releasing lithium ions, an adhesive (17) composed of a polymer material, a dispersant (19), a plurality of conductive agents (21) for increasing the conductivity of the entire positive electrode slurry, and a plurality of composite ceramic particles (30) for guiding the lithium ions. Each composite ceramic particle includes ceramic particles and a carbon layer covering the outer surface of the ceramic particle.

Description

[Technical Field]

[0001] The present invention relates to a positive electrode plate for a solid or semi-solid battery, and more particularly to a positive electrode plate with ceramic composite particles formed by phosphoric acids and a carbon layer. [Background technology]

[0002] Batteries are primarily formed by placing electrodes (positive and negative electrodes) in an electrolyte. Conventionally, ionic conductivity is increased by adding ceramic particles to the electrodes. Because the ceramic particles have high ionic conductivity for lithium ions, the dispersed ceramic particles act as guides to disperse lithium ion channels as the lithium ions pass through the electrode. This allows lithium ions to exhibit uniform channel distribution within the electrode, preventing abnormal accumulation of lithium ions in the electrode slurry and side reactions with the electrode slurry. Summary of the Invention [Problem to be solved by the invention]

[0003] However, because conventional ceramic particles have a large amount of oxygen ions on their surfaces, when the conventional ceramic particles are added to the positive electrode slurry during the process, the conventional ceramic particles interact with the solvent in the positive electrode slurry, causing the positive electrode slurry to exhibit strong alkalinity, which deteriorates the positive electrode particles and the positive electrode slurry, increases the process difficulty, and makes it difficult to achieve the expected electrochemical properties of the manufactured positive electrode plate.

[0004] Furthermore, adding a large number of ceramic particles to the positive electrode slurry reduces the electron conduction ability of the positive electrode slurry. Although this problem can be improved by adding more conductive material, the proportion of positive electrode particles in the electrode plate decreases, making it difficult to increase the energy density of the battery.

[0005] The inventors believed that the above drawbacks could be overcome, and after extensive research, they came up with a positive electrode plate containing phosphate ceramic particles coated with a carbon layer, which effectively overcomes the above problems through a rational design. The carbon layer can protect the ceramic particles from interacting with the solvent in the positive electrode slurry and improve the electron conduction ability of the positive electrode slurry, thereby resolving the above-mentioned drawbacks of the prior art.

[0006] The present invention has been made in view of the above circumstances, and aims to solve the above problems by providing a positive electrode plate including phosphate ceramic particles coated with a carbon layer. [Means for solving the problem]

[0007] To achieve the above object, one embodiment of the present invention provides a positive electrode plate containing the ceramic particles and phosphate ceramic particles coated with a carbon layer, in which the surfaces of the ceramic particles are coated with a carbon layer to form composite ceramic particles. The carbon layer can protect the ceramic particles inside to prevent side reactions between the ceramic particles and the solvent in the positive electrode slurry. By disposing multiple composite ceramic particles in the positive electrode slurry, the present invention can increase the conductivity of the entire positive electrode. [Effects of the Invention]

[0008] Thus, the present invention has the following advantages: In the present invention, the surface of a ceramic particle is coated with a carbon layer to form a composite ceramic particle, which can protect the ceramic particle from side reactions with the solvent in the positive electrode slurry. By disposing multiple composite ceramic particles in the positive electrode slurry, the present invention can improve the conductivity of the entire positive electrode.

[0009] Other objects, configurations and effects of the present invention will become apparent from the following detailed description of the preferred embodiments of the present invention. [Brief explanation of the drawings]

[0010] [Figure 1] 1 shows an example of a positive electrode plate including composite ceramic particles coated with a carbon layer according to the present invention. [Figure 2] 1 is a cross-sectional view showing the structure of a positive electrode plate including composite ceramic particles coated with a carbon layer in accordance with an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention will be described below with reference to the accompanying drawings, in which: FIG. 1 is a block diagram of a conventional optical fiber cable; FIG. 2 is a block diagram of a conventional optical fiber cable;

[0012] Hereinafter, an embodiment of a positive electrode plate 11 including composite ceramic particles coated with a carbon layer according to the present invention will be described in detail with reference to FIGS.

[0013] The positive electrode plate 11 is used in a solid-state or semi-solid-state battery, and the solid-state or semi-solid-state battery includes a positive electrode 10, a negative electrode 40, and a dielectric thin film layer 45 attached between the positive electrode 10 and the negative electrode 40. The positive electrode 10 includes the positive electrode plate 11.

[0014] The positive electrode plate 11 includes a positive electrode substrate 12 on which the material of the positive electrode 10 is placed, and a positive electrode slurry layer 13 applied to the positive electrode substrate 12. The positive electrode slurry layer 13 is composed of a positive electrode slurry 14.

[0015] The positive electrode slurry 14 includes the following components: The configuration of each component will be described below.

[0016] The positive electrode particles 15 are used to store or release lithium ions. The positive electrode particles 15 are selected from lithium cobalt oxide (LiCoO2, LCO) particles, lithium nickel manganese cobalt oxide (NCM) particles, etc. Each positive electrode particle 15 is an active material. The weight percentage of the positive electrode particles 15 in the positive electrode slurry layer 13 ranges from 92 wt% to 98 wt%.

[0017] The adhesive 17 is made of a polymer material such as PVDF (polyvinylidene difluoride), PVP (polyvinyl pyrrolidone), or PEO (poly(oxyethylene)), and the weight percentage of the adhesive 17 in the positive electrode slurry layer 13 is in the range of 0.5 wt % to 3.0 wt %.

[0018] The dispersant 19 is composed of at least one of benzenesulfonates (besylate), ammonium bromide (NH4Br), and Triton X-100. The weight ratio of the adhesive 17 to the dispersant 19 is 7:3. The dispersant 19 is used to disperse the materials of the positive electrode slurry 14 so that they do not aggregate.

[0019] The conductive agents 21 are made of at least one of carbon nanotubes, graphene, and amorphous carbon. The weight percentage of the conductive agents 21 in the positive electrode slurry layer 13 ranges from 0.5 wt % to 2.5 wt %. The conductive agents 21 are used to increase the conductivity of the entire positive electrode slurry 14.

[0020] The plurality of composite ceramic particles 30 are used to guide lithium ions and disperse lithium ion channels to prevent abnormal accumulation of lithium ions in the positive electrode slurry 14 and side reactions with the positive electrode slurry 14. As shown in FIG. 2, each composite ceramic particle 30 includes a ceramic particle 301 and a carbon layer 302 covering the outer surface of the ceramic particle 301. The weight percentage of the plurality of composite ceramic particles 30 in the positive electrode slurry layer 13 is in the range of 0.1 wt% to 1.5 wt%. The size of each composite ceramic particle 30 is less than 200 nm.

[0021] The plurality of positive electrode particles 15 are distributed so as to be dispersed in the positive electrode slurry layer 13, and the conductive agent 21 and the plurality of composite ceramic particles 30 are dispersed among the plurality of positive electrode particles 15. The adhesive 17 is used to adhere the plurality of positive electrode particles 15, the conductive agent 21, and the plurality of composite ceramic particles 30, and the dispersant 19 is used to disperse the plurality of positive electrode particles 15, the conductive agent 21, and the plurality of composite ceramic particles 30, thereby preventing these components from settling at the bottom of the positive electrode slurry 14 due to gravity.

[0022] Because conventional ceramic particles have a large amount of oxygen ions on their surfaces, adding multiple conventional ceramic particles to a cathode slurry during the manufacturing process can cause the ceramic particles to interact with the solvent in the cathode slurry, resulting in a highly alkaline cathode slurry and deterioration of the cathode particles and the cathode slurry. This increases the technical difficulty of the process and makes it difficult to achieve the expected electrochemical properties of the resulting cathode plate. Therefore, the present invention covers the outer surface of each ceramic particle 301 with the carbon layer 302, isolating the oxygen ions on the surface of the ceramic particles 301 from the solvent in the cathode slurry 14, thereby preventing the above-mentioned problems. Furthermore, ceramic particles themselves have high ionic conductivity but are also electronic insulators. Due to their properties, a cathode coating layer containing ceramic particles has higher ionic conductivity than a conventional cathode plate, but its electronic conductivity is reduced. Adding more conductive material can address this issue, but it reduces the proportion of positive particles in the plate, making it difficult to increase the battery's energy density. The carbon layer 302 of the present invention not only isolates the ceramic particles 301 from the solvent in the positive electrode slurry 14, but also enhances the electronic conductivity of the ceramic particles 301. Therefore, the present invention solves all of the above problems by using a plurality of the composite ceramic particles 30 in the positive electrode plate 11.

[0023] The ceramic particles 301 have a lithium ion conducting ability (ionic conductivity is 10 -5 cm 2 / s) or oxides with a garnet or perovskite structure.

[0024] The ceramic oxides or phosphates having lithium ion conducting capability are, for example, lithium aluminum titanium phosphate (LATP) or lithium aluminum germanium phosphate (LAGP) having a NASICON (sodium (Na) super ionic conductor) structure, or phosphates such as lithium phosphate (Li3PO4) having lithium conducting capability. The oxides having a garnet or perovskite structure are, for example, lithium lanthanum zirconium oxide (Li7La3Zr2O 12 The ceramic particles 301 are also made of a combination of the above-mentioned components in any ratio.

[0025] The ceramic particles 301 are made of an LLZO material, which is at least one of LLZO, Ga-LLZO (Ga-doped LLZO, gallium-doped lithium lanthanum zirconium oxide), Cu-LLZO (Cu-doped LLZO, copper-doped lithium lanthanum zirconium oxide), Ta-LLZO (Ta-doped LLZO, tantalum-doped lithium lanthanum zirconium oxide), Sr-LLZO (Sr-doped LLZO, strontium-doped lithium lanthanum zirconium oxide), and Al-LLZO (Al-doped LLZO, aluminum-doped lithium lanthanum zirconium oxide).

[0026] When the ceramic particles 301 are made of LAGP, the LAGP is Li 1+x Al x Ge 2-x (PO4)3 or Li 1+x+y Al x Ge 2-x-y-z M y Nz (PO4)3. When the ceramic particles 301 are made of LATP, the LATP is selected from Li 1+x Al x Ti 2-x (PO4)3 or Li 1+x+y Al x Ti 2-x-y-z M y N z (PO4)3, where x is in the range of 0.1 to 0.8, y is in the range of 0 to 0.2, and z is in the range of 0 to 0.2. M is selected from Sc 3+ (Scandium ion), Y 3+ (yttrium ion), Ga 3+ (Gallium ion), In 3+ (indium ion), La 3+ (lanthanum ion) and other trivalent cations. 4+ (zirconium ion), Si 4+ (silicon ion), Sn 4+ (tin ion) and other tetravalent cations.

[0027] The carbon layer 302 covers the outer surface of the ceramic particle 301. The radial thickness of the carbon layer 302 is less than 10 nm. The carbon layer 302 itself has good electrical conductivity and can prevent excessive volume expansion when the ceramic particle 301 is filled with lithium ions. Therefore, the carbon layer 302 can achieve a protective function.

[0028] As shown in FIG. 2, the carbon layer 302 includes amorphous carbon 52, and the amorphous carbon 52 is formed of at least one of the following: (i) Hard carbon or soft carbon formed by sintering and debinding organic resins, or hard carbon or soft carbon formed by sintering and debinding organic carbohydrates. (ii) Amorphous carbon formed from an organic compound in a reducing atmosphere. The organic compound is selected from carbohydrates (e.g., monosaccharides, disaccharides, oligosaccharides, polysaccharides), water-soluble fibers, amino acid polymers, etc. Preferably, the organic compound is a carbon-containing compound containing at least one element selected from nitrogen, fluorine, phosphorus, and sulfur. The carbon is doped with these elements (i.e., nitrogen, fluorine, phosphorus, or sulfur) through a reduction reaction, thereby increasing the electronic conductivity of the composite ceramic particles 30. (iii) Amorphous carbon formed by dehydration of carbohydrates. (iv) Amorphous carbon containing multiple carbon skeletons and partial functional groups, formed by dehydration of water-soluble fibers. (v) Amorphous carbon formed by dehydration of amino acid polymers, which is composed of multiple carbon skeletons with straight chains or side chains containing doping elements.

[0029] A plurality of graphene sheets 54 are further mixed in the carbon layer 302. The graphene sheets 54 are multi-layer graphene having 2 to 10 layers, and the sheet diameter of the graphene sheets 54 is less than 500 nm. Each of the graphene sheets 54 has a sheet-like structure, and the plurality of graphene sheets 54 form a multilayer structure that coats the outer periphery of the ceramic particle 30 in layers.

[0030] A plurality of carbon nanotubes 56 are further mixed into the carbon layer 302. Each of the carbon nanotubes 56 has a size of less than 1 μm. Gaps are formed between the graphene sheets 54 and the ceramic particles 301, and the carbon nanotubes 56 serve as bridges between the graphene sheets 54 and the ceramic particles 301 or between different graphene sheets 54, further enhancing the electronic conductivity of each composite ceramic particle 30.

[0031] In each of the composite ceramic particles 30, the weight ratio of the ceramic particles 301 to the carbon layers 302 is 99.5:0.5. The weight ratio of the total weight of the graphene sheets 54 to the total weight of the carbon nanotubes 56 is 4:1.

[0032] 2, a plurality of lithium fluoride (LiF) particles 55 are further mixed in the carbon layer 302. Since the efficiency of lithium ions passing through the composite ceramic particle 30 is affected by the thickness of the carbon layer 302, the plurality of lithium fluoride particles 55 are used as jumping boards for the lithium ions, so that the lithium ions pass through the composite ceramic particle 30 by the plurality of lithium fluoride particles 55, helping to guide the lithium ions. The plurality of lithium fluoride particles 55 form an island-like distribution morphology.

[0033] The particle size of the lithium fluoride particles 55 is less than 5 nm. In each of the composite ceramic particles 30, the weight ratio of the ceramic particles 301 to the total weight of the plurality of lithium fluoride particles 55 is in the range of 99.9 to 99.95:0.1 to 0.05.

[0034] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means devised in different embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0035] 10 positive electrode 11 Positive electrode plate 12 Positive electrode substrate 13 Positive electrode slurry layer 14 Positive electrode slurry 15 Positive electrode particles 17 Adhesive 19 Dispersants 21 Conductive agent 30 Composite ceramic particles 40 negative electrode 45 Dielectric Thin Film Layer 52 Amorphous Carbon 54 Graphene Sheet 55 Lithium fluoride particles 56 Carbon nanotubes 301 Ceramic particles 302 Carbon layer

Claims

1. A positive electrode plate including composite ceramic particles coated with a carbon layer for use in a solid or semi-solid battery, the solid or semi-solid battery including a positive electrode, a negative electrode, and a dielectric thin film layer applied between the positive electrode and the negative electrode, the positive electrode including the positive electrode plate; The positive electrode plate is a positive electrode substrate for placing the positive electrode material thereon; a positive electrode slurry layer applied to the positive electrode substrate, the positive electrode slurry layer being composed of a positive electrode slurry; The positive electrode slurry is a plurality of positive electrode particles adapted to store or release lithium ions, each of said positive electrode particles being an active material; an adhesive made of a polymer material; a dispersant; and a plurality of conductive agents for increasing the conductivity of the entire positive electrode slurry; A positive electrode plate comprising a plurality of composite ceramic particles coated with a carbon layer, the composite ceramic particles being used to guide lithium ions so as to disperse lithium ion channels to prevent abnormal accumulation of lithium ions in a positive electrode slurry and the occurrence of a side reaction with the positive electrode slurry, the composite ceramic particles each comprising a ceramic particle and a carbon layer coating the outer surface of the ceramic particle.

2. The carbon layer comprises amorphous carbon, the amorphous carbon comprising: hard carbon or soft carbon formed by sintering and debinding organic resins or organic carbohydrates; Amorphous carbon formed from organic compounds in a reducing atmosphere; amorphous carbon formed by dehydration of carbohydrates; Amorphous carbon containing multiple carbon skeletons and partial functional groups, which is formed by dehydrating water-soluble fibers; 2. A positive electrode plate comprising phosphate-based ceramic particles coated with a carbon layer according to claim 1, characterized in that the positive electrode plate is formed from at least one of amorphous carbon formed by dehydrating an amino acid polymer and amorphous carbon formed from multiple linear or side chain carbon skeletons containing doping elements.

3. 3. The positive electrode plate comprising phosphate-based ceramic particles coated with a carbon layer according to claim 2, wherein the organic compound is a carbohydrate, and the carbohydrate is at least one selected from the group consisting of monosaccharides, disaccharides, oligosaccharides, polysaccharides, water-soluble fibers, and amino acid polymers.

4. 3. The positive electrode plate comprising phosphate-based ceramic particles coated with a carbon layer according to claim 2, wherein the organic compound is a carbon-containing compound containing at least one element selected from the group consisting of nitrogen, fluorine, phosphorus, and sulfur.

5. 2. The positive electrode plate according to claim 1, wherein the particle size of each of the composite ceramic particles is less than 200 nm, and the radial thickness of the carbon layer is less than 10 nm.

6. 2. The positive electrode plate according to claim 1, wherein the weight ratio of the ceramic particles to the carbon layer in each composite ceramic particle is 99.5:0.

5.

7. 2. The positive electrode plate according to claim 1, wherein a weight percentage of the positive electrode particles in the positive electrode slurry layer is between 92 wt % and 98 wt %, a weight percentage of the adhesive in the positive electrode slurry layer is between 0.5 wt % and 3.0 wt %, a weight ratio of the adhesive to the dispersant is 7:3, a weight percentage of the conductive agents in the positive electrode slurry layer is between 0.5 wt % and 2.5 wt %, and a weight percentage of the composite ceramic particles in the positive electrode slurry layer is between 0.1 wt % and 1.5 wt %.

8. The ceramic particles have a lithium ion conductivity of 10 -５ cm ２ 2. The positive electrode plate comprising phosphate-based ceramic particles coated with a carbon layer according to claim 1, characterized in that the positive electrode plate is formed of at least one of ceramic oxides or phosphates having a porosity of more than 1 / s, garnet, or oxides having a perovskite structure.

9. The ceramic oxides or phosphates having lithium ion conductivity include, for example, lithium aluminum titanium phosphate (LATP), lithium germanium aluminum phosphate (LAGP), and lithium phosphate (Li) having a NASICON (sodium (Na) super ionic conductor) structure. ３ P.O. ４ 9. The positive electrode plate according to claim 8, wherein at least one of the following is selected from the group consisting of phosphate ceramic particles coated with a carbon layer.

10. When the ceramic particles are composed of LAGP, the LAGP is Li １＋ｘ Al ｘ Ge ２-ｘ (P.O. ４ ) ３ and Li １＋ｘ＋ｙ Al ｘ Ge ２-ｘ-ｙ-ｚ M ｙ N ｚ (P.O. ４ ) ３ When the ceramic particles are composed of LATP, the LATP is selected from Li １＋ｘ Al ｘ Ti ２-ｘ (P.O. ４ ) ３ and Li １＋ｘ＋ｙ Al ｘ Ti ２-ｘ-ｙ-ｚ M ｙ N ｚ (P.O. ４ ) ３ wherein x is in the range of 0.1 to 0.8, y is in the range of 0 to 0.2, z is in the range of 0 to 0.2, M is a trivalent cation, and N is a tetravalent cation.

11. M is Sc ３＋ (Scandium ion), Y ３＋ (yttrium ion), Ga ３＋ (Gallium ion), In ３＋ (indium ion), La ３＋ 11. The positive electrode plate comprising phosphate ceramic particles coated with a carbon layer according to claim 10, characterized in that the phosphate ceramic particles are selected from the group consisting of lanthanum ions, ...

12. The positive electrode plate according to claim 1 , wherein a plurality of graphene sheets are further mixed in the carbon layer.

13. 13. The positive electrode plate comprising phosphate-based ceramic particles coated with a carbon layer according to claim 12, wherein each of the graphene sheets is a multi-layer graphene having 2 to 10 layers, and the sheet diameter of each of the graphene sheets is less than 500 nm.

14. 2. The positive electrode plate according to claim 1, wherein a plurality of carbon nanotubes are further mixed in the carbon layer.

15. 2. The positive electrode plate according to claim 1, wherein a plurality of graphene sheets and a plurality of carbon nanotubes are further mixed in the carbon layer, and a weight ratio of a total weight of the plurality of graphene sheets to a total weight of the plurality of carbon nanotubes is 4:

1.

16. 2. The positive electrode plate according to claim 1, wherein a plurality of lithium fluoride particles are further mixed in the carbon layer, the plurality of lithium fluoride particles being used as springboards for lithium ion channels, and the lithium ions pass through the composite ceramic particles via the plurality of lithium fluoride particles, thereby helping to guide the lithium ions, and the plurality of lithium fluoride particles forming an island-like distribution morphology.

17. The positive electrode particles are lithium cobalt oxide (LiCoO ２ 2. The positive electrode plate according to claim 1, wherein the conductive material is selected from the group consisting of lithium phosphate-based ceramic particles (LCO) particles and lithium nickel manganese cobalt oxide (NCM) particles, the adhesive is formed of at least one of PVDF, PVP, and PEO, the dispersant is formed of at least one of benzenesulfonates, ammonium bromide salts, and Triton, and the conductive material is selected from the group consisting of carbon nanotubes, graphene, and amorphous carbon.

18. N is Zr ４＋ (zirconium ion), Si ４＋ (silicon ion), Sn ４＋ 11. The positive electrode plate comprising phosphate ceramic particles coated with a carbon layer according to claim 10, characterized in that the phosphate ceramic particles are selected from the group consisting of tin ions, ...

Images