Conductive slurry for xBC battery, preparation method, electrode and battery

Abstract

The invention provides conductive paste for an xBC battery, a preparation method, an electrode and a battery, and belongs to the field of xBC batteries. The conductive paste consists of the following components: 50-80 parts of silver powder, 5-25 parts of silver-coated tungsten, 1.5-5.5 parts of a glass material, 10-15 parts of an organic carrier and 0.5-2 parts of an additive, wherein the silver powder is composed of chain-shaped silver powder, dendritic silver powder, hollow spherical silver powder, micro-nano net-shaped silver powder, micron-sized spherical silver powder, nano-sized spherical silver powder and flaky silver powder. Firstly, a complex and compact conductive network is formed through optimized combination of silver powder of various shapes, and contact resistance and bulk resistance are remarkably reduced; secondly, through the synergistic effect of the silver-coated tungsten core-shell structure and the silver powder, the resistance is further reduced, and meanwhile the high-temperature stability and the mechanical strength are enhanced; and finally, silver-coated tungsten is used for replacing part of silver powder, and meanwhile, excellent conductivity is kept, so that the contact resistance and bulk resistance of the P-region electrode of the xBC battery are reduced.

Description

Technical Field

[0001] The present application relates to the technical field of xBC batteries, and in particular to a conductive paste, a preparation method, an electrode and a battery for xBC batteries. Background Art

[0002] The xBC cell (Interdigitated Back Contact Solar Cell) is a high-efficiency solar cell. Its core feature is that both the positive and negative electrodes are placed on the back of the cell, thus avoiding the front electrode from blocking the light and significantly improving the photoelectric conversion efficiency of the cell. The xBC cell has broad application prospects in the photovoltaic field due to its high efficiency, low light decay and good temperature coefficient.

[0003] The P-zone electrode is the key component responsible for collecting holes (positive charges) in the xBC battery, and its performance directly affects the fill factor (FF) and conversion efficiency of the battery. At present, the ohmic contact between the traditional P-zone electrode and the silicon substrate is not good, resulting in high contact resistance, which affects the collection efficiency of carriers. At the same time, the conductivity of the electrode material itself is insufficient, resulting in a large body resistance, further reducing the efficiency of the battery. In addition, the interface contact between the conductive paste and the silicon substrate is poor, and interface defects are prone to occur, which increases the contact resistance. Therefore, it is urgent to develop a new conductive paste. Summary of the invention

[0004] The present application provides a conductive paste, preparation method, electrode and battery for an xBC battery to solve the following technical problem: how to reduce the contact resistance and body resistance of the electrode in the P region of the xBC battery.

[0005] In a first aspect, the present application provides a conductive paste for an xBC battery, which is composed of the following components, measured in parts by mass: 50 to 80 parts of silver powder, 5 to 25 parts of silver-coated tungsten, 1.5 to 5.5 parts of glass material, 10 to 15 parts of organic carrier, and 0.5 to 2 parts of additives; wherein the silver powder is composed of chain silver powder, dendritic silver powder, hollow spherical silver powder, micro-nano mesh silver powder, micron-sized spherical silver powder, nano-sized spherical silver powder and flaky silver powder.

[0006] Optionally, the mass m1 of the chain-like silver powder, the mass m2 of the dendritic silver powder, the mass m3 of the hollow spherical silver powder, the mass m4 of the micro-nano mesh silver powder, the mass m5 of the micron-sized spherical silver powder, the mass m6 of the nano-sized spherical silver powder and the mass m7 of the flaky silver powder satisfy the following relationship:

[0007] m1:m2:m3:m4:m5:m6:m7=(10~20):(10~20):(5~10):(10~15):(20~30):(10~15):(5~10).

[0008] Optionally, the diameter of the chain-shaped silver powder is 0.1-1 μm, and the length is 5-20 μm; and / or,

[0009] The main trunk diameter of the dendritic silver powder is 0.5 to 2 μm, and the branch length is 1 to 5 μm; and / or,

[0010] The outer diameter of the hollow spherical silver powder is 1 to 5 μm, and the wall thickness is 0.1 to 0.5 μm; and / or,

[0011] The mesh size of the micro-nano mesh silver powder is 0.5-2 μm, and the wire diameter is 0.1-0.5 μm; and / or,

[0012] The particle size of the micron-sized spherical silver powder is 1 to 10 μm; and / or,

[0013] The particle size of the nano-scale spherical silver powder is 20 to 100 nm; and / or,

[0014] The flaky silver powder has a thickness of 0.1 to 0.5 μm and a diameter of 1 to 5 μm.

[0015] Optionally, the glass material consists of the following components, measured in molar percentage: 50-70 mol.%, lead borosilicate glass, 20-40 mol.%, aluminosilicate glass, 1-3 mol.%, bismuth oxide, 1-3 mol.%, zinc oxide, and 0.5-2 mol.% nano-silicon dioxide.

[0016] Optionally, the organic carrier is composed of the following chemical components by mass fraction: 40-60% terpineol, 20-30% ethyl acetate, 1-5% polyether modified siloxane, 10-20% polyvinyl butyral, 1-10% epoxy resin, and 1-10% acrylic resin.

[0017] In a second aspect, the present application provides a method for preparing a conductive paste for an xBC battery according to any one embodiment of the first aspect, the method comprising:

[0018] Pre-treating chain silver powder, dendrite silver powder, hollow spherical silver powder, micro-nano mesh silver powder, micron-sized spherical silver powder, nano-sized spherical silver powder and flake silver powder respectively, and then mixing with part of organic carrier to obtain mixed silver powder;

[0019] The mixed silver powder, silver-coated tungsten, glass material, the remaining part of the organic carrier and additives are mixed to obtain a mixed slurry;

[0020] Under an inert atmosphere, the mixed slurry is subjected to a microwave-ultrasound combined treatment to obtain the conductive slurry.

[0021] Optionally, the microwave-ultrasound combined treatment includes the following parameters: microwave power is 100-200 W, ultrasonic power is 200-300 W, and treatment time is 10s-40s.

[0022] Optionally, the chain-like silver powder, the dendritic silver powder, the hollow spherical silver powder, the micro-nano mesh silver powder, the micron-sized spherical silver powder, the nano-sized spherical silver powder and the flaky silver powder are pretreated respectively, comprising:

[0023] The chain-shaped silver powder and the dendrite-shaped silver powder are mixed with a silane coupling agent to form a coating layer on the surface of the chain-shaped silver powder and the dendrite-shaped silver powder;

[0024] The hollow spherical silver powder and the flake silver powder are subjected to plasma treatment to introduce functional groups on the surfaces of the hollow spherical silver powder and the flake silver powder;

[0025] The micro-nano mesh silver powder, nano-scale spherical silver powder and micron-scale spherical silver powder are subjected to surface passivation treatment to form a nano-scale silver oxide protective layer on the surface of the micro-nano mesh silver powder, nano-scale spherical silver powder and micron-scale spherical silver powder.

[0026] In a third aspect, the present application provides an xBC battery P region electrode, which is prepared using the conductive paste for xBC battery described in any one of the first aspects, and the electrode structure includes a highly conductive bottom layer, an intermediate layer and a protective layer.

[0027] In a fourth aspect, the present application provides an xBC battery, characterized in that it includes a P-region electrode according to the third aspect.

[0028] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:

[0029] The present application provides a conductive paste for xBC batteries, which is composed of the following components: 50 to 80 parts of silver powder, 5 to 25 parts of silver-coated tungsten, 1.5 to 5.5 parts of glass material, 10 to 15 parts of organic carrier, and 0.5 to 2 parts of additives; wherein the silver powder is composed of chain silver powder, dendritic silver powder, hollow spherical silver powder, micro-nano mesh silver powder, micron-sized spherical silver powder, nano-sized spherical silver powder and flaky silver powder. Firstly, through the optimized combination of chain silver powder, dendritic silver powder, hollow spherical silver powder, micro-nano mesh silver powder, micron-sized spherical silver powder, nano-sized spherical silver powder and flake silver powder, a complex and dense conductive network is formed, which significantly reduces the contact resistance and bulk resistance; secondly, through the synergistic effect of the core-shell structure of silver-coated tungsten and silver powder, the resistance is further reduced while the high-temperature stability and mechanical strength are enhanced; finally, by using silver-coated tungsten to replace part of the silver powder, the material cost is significantly reduced while maintaining excellent conductive properties, thereby reducing the contact resistance and bulk resistance of the P-region electrode of the xBC battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings herein are incorporated in and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the description, are used to explain the principles of the present application.

[0031] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0032] Figure 1 A schematic flow chart of a method for preparing a conductive paste for xBC batteries provided in an embodiment of the present application. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0034] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0035] In a first aspect, the present application provides a conductive paste for an xBC battery, which is composed of the following components, measured in parts by mass: 50 to 80 parts of silver powder, 5 to 25 parts of silver-coated tungsten, 1.5 to 5.5 parts of glass material, 10 to 15 parts of organic carrier, and 0.5 to 2 parts of additives; wherein the silver powder is composed of chain silver powder, dendritic silver powder, hollow spherical silver powder, micro-nano mesh silver powder, micron-sized spherical silver powder, nano-sized spherical silver powder and flaky silver powder.

[0036] Silver powder (50-80 parts): As the main conductive phase of the conductive paste, the morphology and particle size distribution of silver powder directly affect the construction of the conductive network. Through the synergistic effect of silver powders with various morphologies and particle sizes, a complex and dense conductive network is formed, which significantly reduces the contact resistance and body resistance, while improving the mechanical properties and process performance of the paste.

[0037] Silver-coated tungsten (5-25 parts): Silver-coated tungsten is a core-shell structure material with an outer layer of silver (high conductivity) and an inner layer of tungsten (high melting point, high mechanical strength). During the sintering process, the silver layer forms a good conductive connection with the silver powder, while the tungsten core provides high temperature stability and mechanical support. At the same time, the silver-coated tungsten and silver powder work synergistically to further reduce resistance. In addition, tungsten, as a base metal, is much more expensive than silver. Therefore, using silver-coated tungsten to replace part of the silver powder in conductive photovoltaic slurries can significantly reduce material costs.

[0038] Glass material (1.5-5.5 parts): Glass material can improve the interface contact during sintering and reduce the contact resistance. At the same time, it can improve the high temperature stability and mechanical strength of the slurry. In addition, it can adjust the thermal expansion coefficient and reduce the interface defects caused by thermal stress.

[0039] Organic carrier (10-15 parts): Organic carrier can optimize the rheological properties of the slurry, making it suitable for screen printing or coating processes. At the same time, it can improve the wettability of the slurry to the substrate and improve the printing or coating effect. In addition, it can promote the complete volatilization of the organic carrier during the sintering process to avoid the influence of residues on the conductive properties.

[0040] Additives (0.5-2 parts): Additives are used to improve the dispersibility, rheology and antioxidant properties of the slurry.

[0041] In some embodiments, the mass m1 of the chain silver powder, the mass m2 of the dendritic silver powder, the mass m3 of the hollow spherical silver powder, the mass m4 of the micro-nano mesh silver powder, the mass m5 of the micron-sized spherical silver powder, the mass m6 of the nano-sized spherical silver powder and the mass m7 of the flaky silver powder satisfy the following relationship:

[0042] m1:m2:m3:m4:m5:m6:m7=(10~20):(10~20):(5~10):(10~15):(20~30):(10~15):(5~10).

[0043] In some embodiments, the diameter of the chain-like silver powder is 0.1 to 1 μm, and the length is 5 to 20 μm; and / or,

[0044] The main trunk diameter of the dendritic silver powder is 0.5 to 2 μm, and the branch length is 1 to 5 μm; and / or,

[0045] The outer diameter of the hollow spherical silver powder is 1 to 5 μm, and the wall thickness is 0.1 to 0.5 μm; and / or,

[0046] The mesh size of the micro-nano mesh silver powder is 0.5-2 μm, and the wire diameter is 0.1-0.5 μm; and / or,

[0047] The particle size of the micron-sized spherical silver powder is 1 to 10 μm; and / or,

[0048] The particle size of the nano-scale spherical silver powder is 20 to 100 nm; and / or,

[0049] The flaky silver powder has a thickness of 0.1 to 0.5 μm and a diameter of 1 to 5 μm.

[0050] It should be noted that silver powders of different morphologies play different roles in the conductive network, as follows:

[0051] Chain-shaped silver powder: has a high aspect ratio and can form a long-range conductive path, significantly reducing contact resistance.

[0052] Dendritic silver powder: has a multi-branch structure, which increases the contact points of the conductive network and reduces the body resistance.

[0053] Hollow spherical silver powder: The low density property improves the rheological properties of the slurry. At the same time, its hollow structure can release internal stress and reduce shrinkage deformation during the sintering process.

[0054] Micro-nano mesh silver powder: has a high specific surface area and a complex mesh structure, providing more conductive pathways and enhancing conductive properties.

[0055] Micron-sized spherical silver powder: As the main filler, it provides basic conductive properties and mechanical strength.

[0056] Nano-scale spherical silver powder: fills the gaps between micron-scale silver powders to improve the density of the conductive network.

[0057] Flake silver powder: has high coverage, enhances the interface contact between the slurry and the substrate, and reduces contact resistance.

[0058] In some embodiments, the glass material consists of the following components, in molar percentage: 50-70 mol.% lead borosilicate glass, 20-40 mol.% aluminosilicate glass, 1-3 mol.% bismuth oxide, 1-3 mol.% zinc oxide, and 0.5-2 mol.% nano-silicon dioxide.

[0059] It should be noted that lead borosilicate glass (PbO-B2O3-SiO2 system) is a typical low-melting glass with good wettability, fluidity and low softening temperature, and is suitable for low-temperature sintering process. In terms of mass fraction, lead borosilicate glass is composed of the following chemical components: PbO: 60%, B2O3: 15%, SiO2: 20%, Al2O3: 3%, Na2O: 2%.

[0060] Aluminosilicate glass (Al2O3-SiO2 system) is a high melting point glass with excellent high temperature stability and mechanical strength, suitable for high temperature sintering process. In terms of mass fraction, aluminosilicate glass is composed of the following chemical components: Al2O3: 30%, SiO2: 60%, CaO: 5%, B2O3: 3%, ZrO2: 2%.

[0061] The glass material softens during the sintering process, and the various components play the following roles:

[0062] Lead borosilicate glass (low melting point): softens at low temperatures, promotes the interface contact between silver powder and substrate, and reduces contact resistance.

[0063] Aluminosilicate glass (high melting point): Remains stable at high temperatures, preventing excessive flow or deformation during sintering.

[0064] Bismuth oxide and zinc oxide: adjust the thermal expansion coefficient of the glass powder to match that of the silver powder and substrate, reducing thermal stress.

[0065] Nano-silicon dioxide: Improve the dispersibility and interface contact effect of glass powder.

[0066] In some embodiments, the organic carrier is composed of the following chemical components by mass fraction: 40-60% terpineol, 20-30% ethyl acetate, 1-5% polyether modified siloxane, 10-20% polyvinyl butyral, 1-10% epoxy resin, and 1-10% acrylic resin.

[0067] The organic carrier provides rheological, wettability and drying properties of the slurry, and its composition is designed as follows:

[0068] Terpineol (high boiling point solvent): provides good rheological properties, suitable for printing process.

[0069] Ethyl acetate (low boiling point solvent): speeds up the drying of the slurry and reduces printing defects.

[0070] Polyether modified siloxane (wetting agent): reduces the surface tension of the slurry and enhances the wettability to the substrate.

[0071] Polyvinyl butyral (thermal decomposition polymer): decomposes into gas during the sintering process, forming a microporous structure and promoting the complete volatilization of the organic carrier.

[0072] In some embodiments, the additive is composed of the following chemical components by mass fraction: ammonium polyacrylate: 20-40%, cellulose ether: 20-40%, benzotriazole: 10-30%, and silane coupling agent: 10-30%.

[0073] Additives are used to improve the dispersibility, rheology and oxidation resistance of slurries:

[0074] Ammonium polyacrylate: Prevents silver powder from agglomerating through electrostatic repulsion or steric hindrance.

[0075] Cellulose ether: adjust the viscosity of the slurry and optimize the rheological properties.

[0076] Benzotriazole: It inhibits the oxidation of silver powder by forming a complex with silver ions on the surface of silver powder.

[0077] Silane coupling agent: enhances the interfacial bonding between silver powder, glass powder and organic carrier.

[0078] Figure 1 A schematic flow chart of a method for preparing a conductive paste for xBC batteries provided in an embodiment of the present application.

[0079] like Figure 1 As shown, in a second aspect, the present application provides a method for preparing a conductive paste for an xBC battery according to any one embodiment of the first aspect, the method comprising:

[0080] S1, pre-treating chain silver powder, dendritic silver powder, hollow spherical silver powder, micro-nano mesh silver powder, micron-sized spherical silver powder, nano-sized spherical silver powder and flake silver powder respectively, and then mixing with part of the organic carrier to obtain mixed silver powder;

[0081] S2, mixing the mixed silver powder, silver-coated tungsten, glass material, the remaining part of the organic carrier and additives to obtain a mixed slurry;

[0082] S3. Under an inert atmosphere, subjecting the mixed slurry to a microwave-ultrasound combined treatment to obtain the conductive slurry.

[0083] In some embodiments, the microwave-ultrasound combined treatment includes the following parameters: microwave power is 100-200 W, ultrasonic power is 200-300 W, and treatment time is 10s-40s.

[0084] Silver particles and glass powder in silver paste can form agglomerates during the preparation process, which will affect the dispersion and conductivity of silver paste. Microwave-ultrasound combined treatment can produce strong vibration and impact, effectively destroying these agglomerate structures and making silver particles and glass powder more evenly dispersed in the organic carrier.

[0085] The penetrating and heating properties of microwaves can rapidly heat up the interior of the blend, accelerating the thermal motion between molecules, thereby promoting the dispersion of silver particles and glass powder in the organic carrier. At the same time, the cavitation effect and micro-jet action of ultrasound can produce a strong stirring effect on a microscopic scale, further promoting the mixing and uniform distribution of the components.

[0086] Therefore, the present application can efficiently disperse silver powder and glass powder through the synergistic effect of microwave and ultrasound, and promote the uniform mixing of organic carrier and solid particles. Microwave heating can quickly soften the organic carrier and improve the mixing efficiency. Ultrasonic cavitation can break up the agglomeration of silver powder and improve the uniformity of dispersion. In an inert atmosphere (such as nitrogen), oxidation of silver powder can be prevented.

[0087] In some embodiments, the pretreatment of the chain silver powder, the dendritic silver powder, the hollow spherical silver powder, the micro-nano mesh silver powder, the micron-sized spherical silver powder, the nano-sized spherical silver powder and the flaky silver powder comprises:

[0088] The chain-shaped silver powder and the dendrite-shaped silver powder are mixed with a silane coupling agent to form a coating layer on the surface of the chain-shaped silver powder and the dendrite-shaped silver powder;

[0089] The hollow spherical silver powder and the flake silver powder are subjected to plasma treatment to introduce functional groups on the surfaces of the hollow spherical silver powder and the flake silver powder;

[0090] The micro-nano mesh silver powder, nano-scale spherical silver powder and micron-scale spherical silver powder are subjected to surface passivation treatment to form a nano-scale silver oxide protective layer on the surface of the micro-nano mesh silver powder, nano-scale spherical silver powder and micron-scale spherical silver powder.

[0091] It should be noted that plasma treatment is a surface modification technology that bombards the material surface with high-energy particles (such as electrons, ions, and free radicals) to introduce functional groups (such as carboxyl, amino, and hydroxyl groups), thereby improving the surface activity and interfacial bonding strength of the material.

[0092] Surface passivation treatment is to form a dense protective layer (such as a silver oxide layer) on the surface of the silver powder to prevent the silver powder from oxidizing during the storage and use of the slurry, while improving its chemical stability.

[0093] In some embodiments, the plasma treatment includes the following parameters: power of 50-100 W, treatment time of 10-20 min, and oxygen flow rate of 30-80 mL / min.

[0094] In some embodiments, the surface passivation treatment uses hydrogen peroxide with a concentration of 1 to 10 wt %, a treatment temperature of 20 to 60° C., and a treatment time of 10 to 60 min.

[0095] In the present application, the dispersibility, chemical stability and interface bonding strength of the silver powder are improved by surface modification treatment.

[0096] Surface coating treatment of chain-like silver powder and dendritic silver powder: Silane coupling agent forms an organic coating layer on the surface of silver powder to reduce surface energy and reduce agglomeration.

[0097] Plasma treatment of hollow spherical silver powder and flake silver powder: introducing functional groups such as carboxyl and amino groups on the surface of silver powder to enhance compatibility with organic carriers.

[0098] Surface passivation treatment of micro-nano mesh silver powder, nano-scale spherical silver powder and micron-scale spherical silver powder: forming a nano-scale silver oxide protective layer to prevent oxidation.

[0099] In a third aspect, the present application provides an xBC battery P region electrode, which is prepared using the conductive paste for xBC battery described in any one of the first aspects, and the electrode structure includes a highly conductive bottom layer, an intermediate layer and a protective layer.

[0100] Electrode structure design:

[0101] Through the multi-layer structure design, the contact resistance and body resistance are further reduced. The high-conductivity bottom layer uses a high-silver content paste to provide high conductivity and reduce contact resistance. The middle layer can use this patented conductive paste to form a complex and dense conductive network to reduce body resistance. The protective layer can use a low-silver content paste to provide surface protection to prevent oxidation of the electrode surface.

[0102] In a fourth aspect, the present application provides an xBC battery, characterized in that it includes a P-region electrode according to the third aspect.

[0103] The P-zone electrode is a key component responsible for collecting holes in xBC batteries, and its performance directly affects the battery's fill factor and conversion efficiency. The P-zone electrode prepared by this patented conductive paste has low contact resistance and body resistance, as well as high mechanical strength and anti-oxidation properties.

[0104] In summary, the present application provides a conductive paste for xBC batteries and a preparation method thereof, an electrode and a battery, which have the following significant advantages:

[0105] (1) Excellent electrical conductivity

[0106] Synergistic effect of silver powders with various morphologies: Through the optimized combination of chain silver powder, dendritic silver powder, hollow spherical silver powder, micro-nano mesh silver powder, micron-sized spherical silver powder, nano-sized spherical silver powder and flake silver powder, a complex and dense conductive network is formed, which significantly reduces contact resistance and body resistance.

[0107] Introduction of silver-coated tungsten: The core-shell structure of silver-coated tungsten (the silver layer provides high conductivity and the tungsten core provides high-temperature stability) works synergistically with silver powder to further reduce resistance while enhancing high-temperature stability and mechanical strength.

[0108] (2) Cost advantage

[0109] Silver-coated tungsten replaces part of the silver powder: Tungsten is a base metal, and its price is much lower than silver. Using silver-coated tungsten to replace part of the silver powder can significantly reduce the material cost while maintaining excellent conductive properties.

[0110] (3) Excellent process performance

[0111] Optimization design of organic carrier: Through the composite system of high boiling point solvent (pinene alcohol) and low boiling point solvent (ethyl acetate), the rheological properties and drying properties of the slurry are optimized to make it suitable for screen printing or coating processes.

[0112] Synergistic effect of additives: The multifunctional system of dispersant, rheology modifier, antioxidant and surfactant improves the dispersibility, rheology and antioxidant properties of the slurry, ensuring the process applicability and storage stability of the slurry.

[0113] (4) Excellent interface contact and sintering performance

[0114] Composite design of glass materials: The composite system of low-melting point glass powder (lead borosilicate glass) and high-melting point glass powder (aluminosilicate glass) optimizes the sintering performance and interface contact effect, reduces contact resistance, and improves high-temperature stability and mechanical strength.

[0115] Thermal expansion coefficient matching: By adding bismuth oxide, zinc oxide and nano-silicon dioxide, the thermal expansion coefficient of the glass powder is adjusted to match that of the silver powder and the substrate, reducing interface defects caused by thermal stress.

[0116] (5) Application of surface modification technology

[0117] Plasma treatment: Introduce functional groups such as carboxyl and amino groups on the surface of hollow spherical silver powder and flaky silver powder to enhance their compatibility with organic carriers and improve their dispersibility and interface bonding strength.

[0118] Surface passivation treatment: A nanometer-level silver oxide protective layer is formed on the surface of micro-nano mesh silver powder, nanometer-level spherical silver powder and micrometer-level spherical silver powder to prevent the silver powder from oxidation and improve chemical stability.

[0119] (6) Efficient preparation process

[0120] Microwave-ultrasonic combined treatment: Through the synergistic effect of microwave heating and ultrasonic cavitation, silver powder and glass powder are efficiently dispersed, promoting uniform mixing of organic carriers and solid particles while preventing oxidation of silver powder.

[0121] Inert atmosphere protection: In the preparation process, inert gas (such as nitrogen) is introduced to prevent silver powder oxidation and ensure the high performance of the slurry.

[0122] (7) Electrode structure design optimization

[0123] Multilayer electrode structure: Through the design of high-conductive bottom layer, middle layer and protective layer, the contact resistance and body resistance are further reduced, while the mechanical strength and anti-oxidation performance of the electrode are improved.

[0124] Highly conductive base layer: High silver content paste provides high conductivity and reduces contact resistance.

[0125] Middle layer: This patented conductive paste forms a complex and dense conductive network to reduce bulk resistance.

[0126] Protective layer: Low silver content paste provides surface protection to prevent oxidation of the electrode surface.

[0127] (8) Improved battery performance

[0128] Excellent performance of P-zone electrode: The P-zone electrode prepared by this patented conductive paste has low contact resistance and body resistance, as well as high mechanical strength and anti-oxidation properties, which significantly improves the conversion efficiency and service life of the xBC battery.

[0129] (9) Environmental protection and sustainability

[0130] Reduce the amount of silver powder used: Replacing part of the silver powder with silver-coated tungsten not only reduces costs, but also reduces dependence on precious metal silver, which meets the requirements of sustainable development.

[0131] No harmful substances: Both glass materials and organic carriers are made of environmentally friendly components, avoiding the use of harmful substances and meeting the requirements of green manufacturing.

[0132] This application solves the contact resistance and body resistance problems of the P-zone electrode of the xBC battery by optimizing the composition, preparation process and electrode structure design of the conductive paste, while improving the mechanical properties, oxidation resistance and process applicability of the electrode. This technology has multiple advantages such as excellent conductivity, low cost, good process performance, excellent interface contact and sintering performance, which can significantly improve the efficiency and service life of the xBC battery and has important industrial application value.

[0133] The present application will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are intended only to illustrate the present application and are not intended to limit the scope of the present application. The experimental methods for which specific conditions are not specified in the following examples are usually measured according to industry standards. If there is no corresponding industry standard, then the conditions recommended by the manufacturer are followed.

[0134] Example 1

[0135] The present embodiment provides a conductive paste for xBC batteries, which consists of the following components, measured by mass: 70 parts of silver powder, 15 parts of silver-coated tungsten (AgW50), 2 parts of glass material, 12 parts of organic carrier, and 1 part of additive; wherein the silver powder consists of chain silver powder, dendritic silver powder, hollow spherical silver powder, micro-nano mesh silver powder, micron-sized spherical silver powder, nano-sized spherical silver powder and flaky silver powder.

[0136] The mass m1 of the chain-like silver powder, the mass m2 of the dendrite-like silver powder, the mass m3 of the hollow spherical silver powder, the mass m4 of the micro-nano mesh-like silver powder, the mass m5 of the micron-sized spherical silver powder, the mass m6 of the nano-sized spherical silver powder and the mass m7 of the flaky silver powder satisfy the following relationship:

[0137] m1:m2:m3:m4:m5:m6:m7=15:15:8:12:25:12:8.

[0138] The diameter of the chain silver powder is in the range of 0.1 to 1 μm, and the length is in the range of 5 to 20 μm; the trunk diameter of the dendritic silver powder is in the range of 0.5 to 2 μm, and the branch length is in the range of 1 to 5 μm; the outer diameter of the hollow spherical silver powder is in the range of 1 to 5 μm, and the wall thickness is in the range of 0.1 to 0.5 μm; the mesh size of the micro-nano mesh silver powder is in the range of 0.5 to 2 μm, and the wire diameter is in the range of 0.1 to 0.5 μm; the particle size of the micron-level spherical silver powder is in the range of 1 to 10 μm; the particle size of the nano-level spherical silver powder is in the range of 20 to 100 nm; the thickness of the flaky silver powder is in the range of 0.1 to 0.5 μm, and the diameter is in the range of 1 to 5 μm.

[0139] In terms of molar percentage, the glass material consists of the following components: 60 mol.%, lead borosilicate glass, 32 mol.%, aluminosilicate glass, 3 mol.%, bismuth oxide, 3 mol.%, zinc oxide, and 2 mol.% nano-silicon dioxide.

[0140] The organic carrier is composed of the following chemical components by mass fraction: 50% terpineol, 25% ethyl acetate, 3% polyether-modified siloxane, 12% polyvinyl butyral, 5% epoxy resin and 5% acrylic resin.

[0141] The additive consists of the following chemical components by mass fraction: ammonium polyacrylate: 30%, cellulose ether: 30%, benzotriazole: 20%, and acetyltrimethoxysilane: 20%.

[0142] Based on the above-mentioned conductive paste for xBC battery, this embodiment also provides a method for preparing the conductive paste for xBC battery described in any one of the above-mentioned embodiments, the method comprising:

[0143] S11, pre-treating chain silver powder, dendritic silver powder, hollow spherical silver powder, micro-nano mesh silver powder, micron-sized spherical silver powder, nano-sized spherical silver powder and flaky silver powder respectively, and then mixing with part of the organic carrier to obtain mixed silver powder;

[0144] S21, mixing the mixed silver powder, silver-coated tungsten, glass material, the remaining part of the organic carrier and additives to obtain a mixed slurry;

[0145] S31, in an inert atmosphere, subjecting the mixed slurry to a microwave-ultrasound combined treatment to obtain the conductive slurry. The microwave-ultrasound combined treatment includes the following parameters: microwave power is 150 W, ultrasonic power is 250 W, and treatment time is 25 s.

[0146] The pretreatment of the chain silver powder, the dendritic silver powder, the hollow spherical silver powder, the micro-nano mesh silver powder, the micron-sized spherical silver powder, the nano-sized spherical silver powder and the flaky silver powder comprises:

[0147] The chain-shaped silver powder and the dendritic silver powder are mixed with acetyltrimethoxysilane to form a coating layer on the surface of the chain-shaped silver powder and the dendritic silver powder;

[0148] The hollow spherical silver powder and the flaky silver powder are subjected to plasma treatment to introduce functional groups on the surfaces of the hollow spherical silver powder and the flaky silver powder; the plasma treatment includes the following parameters: power of 70 W, treatment time of 15 min, and oxygen flow rate of 50 mL / min.

[0149] The micro-nano mesh silver powder, nano-scale spherical silver powder and micron-scale spherical silver powder are subjected to surface passivation treatment to form a nano-scale silver oxide protective layer on the surface of the micro-nano mesh silver powder, nano-scale spherical silver powder and micron-scale spherical silver powder. The surface passivation treatment uses hydrogen peroxide with a concentration of 7wt%, a treatment temperature of 40°C and a treatment time of 40min.

[0150] Example 2

[0151] The present embodiment provides a conductive paste for xBC batteries, which consists of the following components, measured by mass: 80 parts of silver powder, 5 parts of silver-coated tungsten (AgW50), 3 parts of glass material, 10 parts of organic carrier, and 2 parts of additives; wherein the silver powder consists of chain silver powder, dendritic silver powder, hollow spherical silver powder, micro-nano mesh silver powder, micron-sized spherical silver powder, nano-sized spherical silver powder and flaky silver powder.

[0152] The mass m1 of the chain-like silver powder, the mass m2 of the dendrite-like silver powder, the mass m3 of the hollow spherical silver powder, the mass m4 of the micro-nano mesh-like silver powder, the mass m5 of the micron-sized spherical silver powder, the mass m6 of the nano-sized spherical silver powder and the mass m7 of the flaky silver powder satisfy the following relationship:

[0153] m1:m2:m3:m4:m5:m6:m7=20:20:10:15:30:15:10.

[0154] The diameter of the chain silver powder is in the range of 0.1 to 1 μm, and the length is in the range of 5 to 20 μm; the trunk diameter of the dendritic silver powder is in the range of 0.5 to 2 μm, and the branch length is in the range of 1 to 5 μm; the outer diameter of the hollow spherical silver powder is in the range of 1 to 5 μm, and the wall thickness is in the range of 0.1 to 0.5 μm; the mesh size of the micro-nano mesh silver powder is in the range of 0.5 to 2 μm, and the wire diameter is in the range of 0.1 to 0.5 μm; the particle size of the micron-level spherical silver powder is in the range of 1 to 10 μm; the particle size of the nano-level spherical silver powder is in the range of 20 to 100 nm; the thickness of the flaky silver powder is in the range of 0.1 to 0.5 μm, and the diameter is in the range of 1 to 5 μm.

[0155] In terms of molar percentage, the glass material consists of the following components: 70 mol.%, lead borosilicate glass, 22 mol.%, aluminosilicate glass, 3 mol.%, bismuth oxide, 3 mol.%, zinc oxide, and 2 mol.% nano-silicon dioxide.

[0156] The organic carrier is composed of the following chemical components by mass fraction: 59% of terpineol, 20% of ethyl acetate, 1% of polyether-modified siloxane, 10% of polyvinyl butyral, 9% of epoxy resin and 1% of acrylic resin.

[0157] The additive consists of the following chemical components by mass fraction: ammonium polyacrylate: 40%, cellulose ether: 20%, benzotriazole: 30%, and acetyltrimethoxysilane: 10%.

[0158] Based on the above-mentioned conductive paste for xBC battery, this embodiment also provides a method for preparing the conductive paste for xBC battery described in any one of the above-mentioned embodiments, the method comprising:

[0159] S11, pre-treating chain silver powder, dendritic silver powder, hollow spherical silver powder, micro-nano mesh silver powder, micron-sized spherical silver powder, nano-sized spherical silver powder and flaky silver powder respectively, and then mixing with part of the organic carrier to obtain mixed silver powder;

[0160] S21, mixing the mixed silver powder, silver-coated tungsten, glass material, the remaining part of the organic carrier and additives to obtain a mixed slurry;

[0161] S31, in an inert atmosphere, subjecting the mixed slurry to a microwave-ultrasound combined treatment to obtain the conductive slurry. The microwave-ultrasound combined treatment includes the following parameters: microwave power is 200 W, ultrasonic power is 300 W, and treatment time is 10 ss.

[0162] The pretreatment of the chain silver powder, the dendritic silver powder, the hollow spherical silver powder, the micro-nano mesh silver powder, the micron-sized spherical silver powder, the nano-sized spherical silver powder and the flaky silver powder comprises:

[0163] The chain-shaped silver powder and the dendritic silver powder are mixed with acetyltrimethoxysilane to form a coating layer on the surface of the chain-shaped silver powder and the dendritic silver powder;

[0164] The hollow spherical silver powder and the flaky silver powder are subjected to plasma treatment to introduce functional groups on the surfaces of the hollow spherical silver powder and the flaky silver powder; the plasma treatment includes the following parameters: power of 100 W, treatment time of 20 min, and oxygen flow rate of 80 mL / min.

[0165] The micro-nano mesh silver powder, nano-scale spherical silver powder and micron-scale spherical silver powder are subjected to surface passivation treatment to form a nano-scale silver oxide protective layer on the surface of the micro-nano mesh silver powder, nano-scale spherical silver powder and micron-scale spherical silver powder. The surface passivation treatment uses hydrogen peroxide with a concentration of 10wt%, a treatment temperature of 60°C and a treatment time of 10.

[0166] Example 3

[0167] The present embodiment provides a conductive paste for xBC batteries, which consists of the following components, measured by mass: 53 parts of silver powder, 25 parts of silver-coated tungsten (AgW50), 5 parts of glass material, 15 parts of organic carrier, and 2 parts of additives; wherein the silver powder consists of chain silver powder, dendritic silver powder, hollow spherical silver powder, micro-nano mesh silver powder, micron-sized spherical silver powder, nano-sized spherical silver powder and flaky silver powder.

[0168] The mass m1 of the chain-like silver powder, the mass m2 of the dendrite-like silver powder, the mass m3 of the hollow spherical silver powder, the mass m4 of the micro-nano mesh-like silver powder, the mass m5 of the micron-sized spherical silver powder, the mass m6 of the nano-sized spherical silver powder and the mass m7 of the flaky silver powder satisfy the following relationship:

[0169] m1:m2:m3:m4:m5:m6:m7=10:10:5:10:20:10:5.

[0170] The diameter of the chain silver powder is in the range of 0.1 to 1 μm, and the length is in the range of 5 to 20 μm; the trunk diameter of the dendritic silver powder is in the range of 0.5 to 2 μm, and the branch length is in the range of 1 to 5 μm; the outer diameter of the hollow spherical silver powder is in the range of 1 to 5 μm, and the wall thickness is in the range of 0.1 to 0.5 μm; the mesh size of the micro-nano mesh silver powder is in the range of 0.5 to 2 μm, and the wire diameter is in the range of 0.1 to 0.5 μm; the particle size of the micron-level spherical silver powder is in the range of 1 to 10 μm; the particle size of the nano-level spherical silver powder is in the range of 20 to 100 nm; the thickness of the flaky silver powder is in the range of 0.1 to 0.5 μm, and the diameter is in the range of 1 to 5 μm.

[0171] In terms of molar percentage, the glass material consists of the following components: 52 mol.%, lead borosilicate glass, 40 mol.%, aluminosilicate glass, 3 mol.%, bismuth oxide, 3 mol.%, zinc oxide, and 2 mol.% nano-silicon dioxide.

[0172] The organic carrier is composed of the following chemical components by mass fraction: 40% of terpineol, 30% of ethyl acetate, 5% of polyether-modified siloxane, 15% of polyvinyl butyral, 1% of epoxy resin and 9% of acrylic resin.

[0173] The additive consists of the following chemical components by mass fraction: ammonium polyacrylate: 20%, cellulose ether: 40%, benzotriazole: 30%, and acetyltrimethoxysilane: 10%.

[0174] Based on the above-mentioned conductive paste for xBC battery, this embodiment also provides a method for preparing the conductive paste for xBC battery described in any one of the above-mentioned embodiments, the method comprising:

[0175] S11, pre-treating chain silver powder, dendritic silver powder, hollow spherical silver powder, micro-nano mesh silver powder, micron-sized spherical silver powder, nano-sized spherical silver powder and flaky silver powder respectively, and then mixing with part of the organic carrier to obtain mixed silver powder;

[0176] S21, mixing the mixed silver powder, silver-coated tungsten, glass material, the remaining part of the organic carrier and additives to obtain a mixed slurry;

[0177] S31, in an inert atmosphere, subjecting the mixed slurry to a microwave-ultrasound combined treatment to obtain the conductive slurry. The microwave-ultrasound combined treatment includes the following parameters: microwave power is 100 W, ultrasonic power is 200 W, and treatment time is 40 s.

[0178] The pretreatment of the chain silver powder, the dendritic silver powder, the hollow spherical silver powder, the micro-nano mesh silver powder, the micron-sized spherical silver powder, the nano-sized spherical silver powder and the flaky silver powder comprises:

[0179] The chain-shaped silver powder and the dendritic silver powder are mixed with acetyltrimethoxysilane to form a coating layer on the surface of the chain-shaped silver powder and the dendritic silver powder;

[0180] The hollow spherical silver powder and the flaky silver powder are subjected to plasma treatment to introduce functional groups on the surfaces of the hollow spherical silver powder and the flaky silver powder; the plasma treatment includes the following parameters: power of 50 W, treatment time of 10 min, and oxygen flow rate of 30 mL / min.

[0181] The micro-nano mesh silver powder, nano-scale spherical silver powder and micron-scale spherical silver powder are subjected to surface passivation treatment to form a nano-scale silver oxide protective layer on the surface of the micro-nano mesh silver powder, nano-scale spherical silver powder and micron-scale spherical silver powder. The surface passivation treatment uses hydrogen peroxide with a concentration of 1wt%, a treatment temperature of 20°C and a treatment time of 60min.

[0182] Comparative Example 1

[0183] This comparative example is modified as follows based on the disclosure of Example 1:

[0184] The silver powder consists of dendritic silver powder, hollow spherical silver powder, micro-nano mesh silver powder, micron-sized spherical silver powder, nano-sized spherical silver powder and flaky silver powder, and no chain silver powder is added.

[0185] Comparative Example 2

[0186] This comparative example is modified as follows based on the disclosure of Example 1:

[0187] The silver powder consists of chain silver powder, hollow spherical silver powder, micro-nano mesh silver powder, micron-sized spherical silver powder, nano-sized spherical silver powder and flaky silver powder, and no dendritic silver powder is added.

[0188] Comparative Example 3

[0189] This comparative example is modified as follows based on the disclosure of Example 1:

[0190] The silver powder consists of chain silver powder, dendrite silver powder, micro-nano mesh silver powder, micron-sized spherical silver powder, nano-sized spherical silver powder and flake silver powder, and no hollow spherical silver powder is added.

[0191] Comparative Example 4

[0192] This comparative example is modified as follows based on the disclosure of Example 1:

[0193] The silver powder consists of chain silver powder, dendrite silver powder, hollow spherical silver powder, micron-sized spherical silver powder, nano-sized spherical silver powder and flaky silver powder, and no micro-nano mesh silver powder is added.

[0194] Comparative Example 5

[0195] This comparative example is modified as follows based on the disclosure of Example 1:

[0196] The silver powder is composed of chain silver powder, dendrite silver powder, hollow spherical silver powder, micro-nano mesh silver powder, micron-sized spherical silver powder and flaky silver powder, and no nano-sized spherical silver powder is added.

[0197] Comparative Example 6

[0198] This comparative example is modified as follows based on Example 1:

[0199] The silver powder is composed of chain silver powder, dendrite silver powder, hollow spherical silver powder, micro-nano mesh silver powder, micron-sized spherical silver powder and flaky silver powder, and no nano-sized spherical silver powder is added.

[0200] Comparative Example 7

[0201] This comparative example is modified as follows based on the disclosure of Example 1:

[0202] The silver powder is composed of chain silver powder, dendrite silver powder, hollow spherical silver powder, micro-nano mesh silver powder, micron-sized spherical silver powder and nano-sized spherical silver powder, and no flaky silver powder is added.

[0203] The xBC battery conductive pastes prepared in Examples 1 to 3 and Comparative Examples 1 to 7 were tested for electrical properties using conventional methods in the art. The test results are listed in Table 1 below.

[0204] Table 1 Electrical properties of conductive pastes for xBC batteries prepared in Examples 1 to 3 and Comparative Examples 1 to 7

[0205] sample NCell Uoc(V) Isc(A) Rsh(Ω) FF(%) Rs(Ω) Example 1 0.1957 0.7215 8.9050 156.9 83.95 0.00105 Example 2 0.1884 0.7101 8.8655 150.6 80.82 0.00176 Example 3 0.1902 0.7165 8.1519 153.4 80.06 0.00198 Comparative Example 1 0.1872 0.7034 7.4012 144.5 78.05 0.00305 Comparative Example 2 0.1765 0.6928 7.8536 132.1 77.51 0.00278 Comparative Example 3 0.1789 0.6915 7.5046 145.7 77.09 0.00274 Comparative Example 4 0.1672 0.6875 7.9525 140.6 76.55 0.00330 Comparative Example 5 0.1812 0.6901 7.7036 138.4 79.01 0.00285 Comparative Example 6 0.1806 0.6987 7.1535 148.2 76.52 0.00381 Comparative Example 7 0.1785 0.7005 7.9015 141.6 76.07 0.00221

[0206] It should be noted that NCell is the number of cells tested. Uoc is the open circuit voltage, which reflects the carrier separation capability. Isc is the short circuit current, which reflects the light absorption capability. Rsh is the parallel resistance, which reflects the leakage current. FF is the fill factor, which reflects the output efficiency. Rs is the series resistance, which reflects the current output capability.

[0207] It can be seen from Table 1 that the NCell of the conductive paste for xBC battery obtained in this embodiment is 0.18-0.20, Uoc is 0.70-0.73V, Isc is 8-9A, Rsh is 150-160Ω, FF is 80-85%, and Rs≤0.002Ω.

[0208] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be understood as a rigid limitation on the scope of the present application; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, the range description from 1 to 6 should be considered to have specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.

[0209] In addition, in the description of the specification of this application, the terms "include", "comprises", etc. mean "including but not limited to". In this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. In this article, "and / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural.

[0210] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A conductive paste for xBC battery, characterized in that: The conductive paste is composed of the following components, in parts by mass: 50 to 80 parts of silver powder, 5 to 25 parts of silver-coated tungsten, 1.5 to 5.5 parts of glass material, 10 to 15 parts of organic carrier, and 0.5 to 2 parts of additives; wherein the silver powder is composed of chain silver powder, dendritic silver powder, hollow spherical silver powder, micro-nano mesh silver powder, micron-sized spherical silver powder, nano-sized spherical silver powder and flaky silver powder.

2. The conductive paste according to claim 1, characterized in that: The mass m1 of the chain silver powder, the mass m2 of the dendrite silver powder, the mass m3 of the hollow spherical silver powder, the mass m4 of the micro-nano mesh silver powder, the mass m5 of the micron-sized spherical silver powder, the mass m6 of the nano-sized spherical silver powder and the mass m7 of the flaky silver powder satisfy the following relationship: m1:m2:m3:m4:m5:m6:m7=(10~20):(10~20):(5~10):(10~15):(20~30):(10~15):(5~10).

3. The conductive paste according to claim 2, characterized in that: The diameter of the chain-shaped silver powder is 0.1 to 1 μm, and the length is 5 to 20 μm; and / or, The main trunk diameter of the dendritic silver powder is 0.5 to 2 μm, and the branch length is 1 to 5 μm; and / or, The outer diameter of the hollow spherical silver powder is 1 to 5 μm, and the wall thickness is 0.1 to 0.5 μm; and / or, The mesh size of the micro-nano mesh silver powder is 0.5-2 μm, and the wire diameter is 0.1-0.5 μm; and / or, The particle size of the micron-sized spherical silver powder is 1 to 10 μm; and / or, The particle size of the nano-scale spherical silver powder is 20 to 100 nm; and / or, The flaky silver powder has a thickness of 0.1 to 0.5 μm and a diameter of 1 to 5 μm.

4. The conductive paste according to claim 1, characterized in that: In terms of molar percentage, the glass material consists of the following components: 50-70 mol.%, lead borosilicate glass, 20-40 mol.%, aluminosilicate glass, 1-3 mol.%, bismuth oxide, 1-3 mol.%, zinc oxide, and 0.5-2 mol.% nano-silicon dioxide.

5. The conductive paste according to claim 1, characterized in that: The organic carrier is composed of the following chemical components by mass fraction: 40-60% terpineol, 20-30% ethyl acetate, 1-5% polyether modified siloxane, 10-20% polyvinyl butyral, 1-10% epoxy resin and 1-10% acrylic resin.

6. A method for preparing a conductive paste for xBC battery according to any one of claims 1 to 5, characterized in that: The method comprises: Pre-treating chain silver powder, dendrite silver powder, hollow spherical silver powder, micro-nano mesh silver powder, micron-sized spherical silver powder, nano-sized spherical silver powder and flake silver powder respectively, and then mixing with part of organic carrier to obtain mixed silver powder; The mixed silver powder, silver-coated tungsten, glass material, the remaining part of the organic carrier and additives are mixed to obtain a mixed slurry; Under an inert atmosphere, the mixed slurry is subjected to a microwave-ultrasound combined treatment to obtain the conductive slurry.

7. The method according to claim 6, characterized in that The microwave-ultrasound combined treatment includes the following parameters: microwave power is 100-200W, ultrasonic power is 200-300W, and treatment time is 10s-40s.

8. The method according to claim 6, characterized in that The chain-like silver powder, the dendritic silver powder, the hollow spherical silver powder, the micro-nano mesh silver powder, the micron-sized spherical silver powder, the nano-sized spherical silver powder and the flaky silver powder are pretreated respectively, including: The chain-shaped silver powder and the dendrite-shaped silver powder are mixed with a silane coupling agent to form a coating layer on the surface of the chain-shaped silver powder and the dendrite-shaped silver powder; The hollow spherical silver powder and the flake silver powder are subjected to plasma treatment to introduce functional groups on the surfaces of the hollow spherical silver powder and the flake silver powder; The micro-nano mesh silver powder, nano-scale spherical silver powder and micron-scale spherical silver powder are subjected to surface passivation treatment to form a nano-scale silver oxide protective layer on the surface of the micro-nano mesh silver powder, nano-scale spherical silver powder and micron-scale spherical silver powder.

9. An xBC battery P-region electrode, characterized in that: The xBC battery is prepared by using the conductive paste according to any one of claims 1 to 5, and the electrode structure includes a highly conductive bottom layer, an intermediate layer and a protective layer.

10. An xBC battery, characterized in that: Comprising the P-region electrode according to claim 9.

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