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CN-122000109-A - Biomass porous carbon composite electrode adaptive to high-voltage series energy storage device and preparation method thereof

CN122000109ACN 122000109 ACN122000109 ACN 122000109ACN-122000109-A

Abstract

The invention discloses a biomass porous carbon composite electrode adapting to a high-voltage series energy storage device and a preparation method thereof, and belongs to the technical field of electrochemical energy storage devices. The composite electrode comprises a metal-based composite copper-aluminum foil current collector, a carbon nano anchoring layer with the thickness of 50-100 nm and a biomass porous carbon active layer, wherein a copper layer on one side of the current collector is coated with a hard carbon negative electrode, and an aluminum layer on the other side of the current collector is coated with an active carbon positive electrode, so that a double-side heteropolar structure is formed. The preparation method comprises the steps of preparing biomass porous carbon, coating an anchoring layer, coating an active layer, drying and rolling. According to the invention, the problems of interfacial binding force and contact impedance of the current collector and the active layer are solved through the carbon nano anchoring layer, the biomass porous carbon is adapted to a high-voltage electrolyte voltage window with the voltage of more than 3.2V, the cycle life is more than or equal to 20 ten thousand times, the cost is reduced by more than 60 percent compared with the traditional carbon material, and the mass production requirement of a multi-layer serial high-voltage energy storage device with the voltage of 800V or more is perfectly adapted.

Inventors

  • Request for anonymity

Assignees

  • 广西钦州市华源电子有限公司

Dates

Publication Date
20260508
Application Date
20260410

Claims (10)

  1. 1. The biomass porous carbon composite electrode is characterized by comprising a metal-based composite copper-aluminum foil current collector, a carbon nano anchoring layer and a biomass porous carbon active layer; one side of the metal matrix composite copper aluminum foil current collector is a copper layer, and the other side of the metal matrix composite copper aluminum foil current collector is an aluminum layer; the carbon nano anchoring layers are coated on the surfaces of two sides of the current collector in a full width mode, and the thickness of the carbon nano anchoring layers is 50-100 nm; The biomass porous carbon active layer is coated on the surface of the carbon nano anchoring layer, the copper layer side is a hard carbon negative electrode active layer, and the aluminum layer side is an active carbon positive electrode active layer, so that a double-side heteropolar composite electrode is formed.
  2. 2. The composite electrode according to claim 1, wherein the carbon nano-anchoring layer is formed by coating carbon nano-tubes or graphene oxide dispersion liquid, and forms a continuous conductive network with the current collector and the biomass porous carbon active layer.
  3. 3. The composite electrode according to claim 1, wherein the biomass porous carbon active layer is made of coconut shell, bamboo charcoal or straw-based biomass carbon, and has a specific surface area of The pore size distribution is 2-50 nm.
  4. 4. The composite electrode according to claim 1, wherein an insulating margin area with a width of 1.5-3 mm is reserved around the composite electrode, and the insulating margin area is free of an active layer and an anchor layer.
  5. 5. The composite electrode according to claim 1, wherein the binding force of the carbon nano-anchor layer with the current collector is more than or equal to 5N/cm, and the binding force with the biomass porous carbon active layer is more than or equal to 8N/cm.
  6. 6. A method for preparing a biomass porous carbon composite electrode according to any one of claims 1 to 5, comprising the steps of: s1, preparing biomass porous carbon, namely preparing biomass porous carbon powder by pretreating, carbonizing and activating biomass raw materials; s2, coating an anchoring layer, namely uniformly coating carbon nano tubes or graphene oxide dispersion liquid on two sides of a metal matrix composite copper aluminum foil current collector, and drying to form the carbon nano anchoring layer; S3, coating an active layer, namely respectively preparing hard carbon negative electrode slurry and active carbon positive electrode slurry, and sequentially coating the slurry on the surfaces of the anchoring layers on the copper layer side and the aluminum layer side of the current collector; S4, drying and rolling, namely drying and rolling the coated electrode to a preset thickness, and cutting to obtain the composite electrode with the preset size.
  7. 7. The preparation method according to claim 6, wherein in the step S1, the activation process adopts a KOH activation method, the activation temperature is 700-900 ℃, and the activation time is 1-3 hours.
  8. 8. The method according to claim 6, wherein in the step S2, the carbon nanotube or graphene oxide dispersion has a solid content of 0.5 to 2wt%, a coating thickness of 50 to 100nm, and a drying temperature of 80 to 120 ℃.
  9. 9. The method according to claim 6, wherein in the step S3, the solid content of the hard carbon negative electrode slurry and the active carbon positive electrode slurry is 40-60 wt% and the coating speed is 5-20 m/min.
  10. 10. The method according to claim 6, wherein in step S4, the rolling pressure is 5 to 15MPa, and the compacted density of the active layer after rolling is 。

Description

Biomass porous carbon composite electrode adaptive to high-voltage series energy storage device and preparation method thereof Technical Field The invention belongs to the technical field of electrochemical energy storage devices and material preparation, and particularly relates to a biomass porous carbon composite electrode adapting to an internal multi-layer serial high-voltage energy storage device with 800V or more and a preparation method thereof. Background In large-scale energy storage scenes such as energy storage in power grid areas and industrial high-voltage standby, the internal multi-layer series high-voltage energy storage devices can directly realize 800V and above high-voltage direct output, and the system structure is greatly simplified. The electrode material is the core of the high-voltage energy storage device, and directly determines the performance and cost of the device. The existing biomass porous carbon patent has the following defects: 1. only the activation process of the material is protected, and no adaptation design aiming at a high-voltage serial scene is adopted; 2. the binding force between the active layer and the current collector is poor, and the active layer is easy to fall off under high-pressure long-cycle, so that the internal resistance is increased, and the capacity is reduced; 3. The electrode design without the adaptation to the internal serial structure of the two different poles cannot be directly applied to a high-voltage direct-out system. At present, no patent exists worldwide for carrying out combined protection on a biomass porous carbon+carbon nano anchoring layer+metal matrix composite copper aluminum foil double-side heteroelectrode structure, so that development of a corresponding composite electrode and a preparation method thereof are needed. Disclosure of Invention The invention aims to provide a biomass porous carbon composite electrode adapting to a high-voltage serial energy storage device and a preparation method thereof, which solve the problems of interface binding force and impedance through a carbon nano anchoring layer, and simultaneously adapt to a double-side heteropolar internal serial structure, thereby greatly reducing the manufacturing cost of the high-voltage energy storage device. In order to achieve the above purpose, the invention adopts the following technical scheme: First aspect of the technical scheme of the composite electrode A biomass porous carbon composite electrode suitable for a high-voltage series energy storage device comprises a metal matrix composite copper-aluminum foil current collector, a carbon nano anchoring layer and a biomass porous carbon active layer. The metal matrix composite copper aluminum foil current collector comprises a copper layer on one side and an aluminum layer on the other side, wherein a carbon nano anchoring layer is coated on two sides of the current collector in a full width mode, the thickness of the carbon nano anchoring layer is 50-100 nm, a biomass porous carbon active layer is coated on the surface of the anchoring layer, the copper layer side is a hard carbon negative electrode, the aluminum layer side is an active carbon positive electrode, and a double-side heteropolar structure is formed. Further, the carbon nano anchoring layer is carbon nano tube or graphene oxide, forms a continuous conductive network, and simultaneously improves the interfacial binding force, wherein the biomass porous carbon is prepared from coconut shells, bamboo charcoal or straw, and has specific surface areaThe pore size distribution is 2-50 nm, and the high-voltage electrolyte with the pore size distribution being more than 3.2V is adapted. Further, an insulating margin area of 1.5-3 mm is reserved around the electrode, and the insulating margin area is perfectly matched with an S02 lossless lamination and S03 edge full encapsulation process, and is used for a high-voltage energy storage device which is internally connected in series in 50-120 layers, and rated working voltage is more than or equal to 800V. Second aspect, preparation method The preparation method of the biomass porous carbon composite electrode comprises the following steps: s1, preparing biomass porous carbon, namely cleaning, crushing and screening biomass raw materials, carbonizing the biomass raw materials for 1h at 500 ℃ in a nitrogen atmosphere, adding KOH according to a basic carbon ratio of 3:1, activating the biomass raw materials for 2h at 800 ℃, pickling, washing the biomass raw materials with water to be neutral, and drying the biomass raw materials to obtain biomass porous carbon powder; s2, coating an anchoring layer, namely uniformly coating carbon nano tube dispersion liquid (solid content of 1 wt%) on two sides of a copper-aluminum composite foil with the thickness of 20 mu m, and drying at 100 ℃ to form a carbon nano anchoring layer with the thickness of 80 nm; S3, coating an active layer, namely respectively preparing