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CN-122000302-A - Silicon-based copper negative electrode plate and preparation method and application thereof

CN122000302ACN 122000302 ACN122000302 ACN 122000302ACN-122000302-A

Abstract

The invention provides a silicon-based copper negative electrode plate, a preparation method and application thereof, and relates to the technical field of battery negative electrodes. The silicon-based copper negative electrode plate comprises at least one copper substrate with a plurality of micropores on the surface, wherein a silicon-carbon composite layer is deposited in the micropores, an aluminum composite layer is deposited on at least one surface of the copper substrate, at least the opening of the micropores is sealed by the aluminum composite layer, and the silicon-carbon composite layer comprises a silicon base layer and a carbon base layer which are deposited in a circulating mode. According to the invention, the silicon-carbon material is circularly deposited in the micropores on the surface of the porous copper foil and is sealed by using the aluminum composite layer, so that the load capacity and the contact area of the copper foil to the silicon-carbon material can be improved, and the stability of the silicon-carbon material on the surface of the copper foil can be improved, thereby effectively improving the energy density and the cycle life of the battery.

Inventors

  • YUE ZHIHAO
  • WEN LIJUN
  • Ma Haoqiang
  • JIN CHENXIN

Assignees

  • 南昌大学
  • 南昌大学共青城光氢储技术研究院

Dates

Publication Date
20260508
Application Date
20260212

Claims (8)

  1. 1. A silicon-based copper negative electrode plate is characterized by comprising a copper substrate, wherein at least one surface of the copper substrate is provided with a plurality of micropores, a silicon-carbon composite layer is deposited in the micropores, an aluminum composite layer is deposited on at least one surface of the copper substrate, the aluminum composite layer at least seals the openings of the micropores, and the silicon-carbon composite layer comprises a silicon base layer and a carbon base layer which are deposited in a circulating mode.
  2. 2. The silicon-based copper negative electrode sheet according to claim 1, wherein the pore diameter of the micropores is 1nm-400nm, and/or the density of the micropores on the surface of the copper substrate is 50000 micropores per cm 2 -100000 micropores 2 , and/or the total pore volume of the micropores is 0.15cm 3 -0.35cm 3 , and/or the thickness of the aluminum composite layer is 1nm-300nm, and/or the thickness of the copper substrate is 8 μm, and/or the silicon-based layer comprises amorphous silicon or amorphous silicon oxide.
  3. 3. The silicon-based copper negative electrode tab according to claim 1, wherein the silicon-based layer has a thickness of 0.1 μm to 1.2 μm, and/or the carbon-based layer has a thickness of 0.1 μm to 0.6 μm, and/or the silicon-based layer and the carbon-based layer are deposited cyclically 1 to 3 times, and/or the silicon-carbon composite layer has a thickness of 0.5 μm to 3.0 μm, and/or the aluminum composite layer is formed by composite deposition of aluminum oxide and aluminum fluoride.
  4. 4. A method for producing a silicon-based copper negative electrode sheet according to any one of claims 1 to 3, comprising polishing the surface of a copper substrate and depositing an aluminum composite layer after the surface of the copper substrate having the microporous opening is circularly deposited with a silicon-based material and a carbon-based material for a predetermined number of cycles.
  5. 5. The method of claim 4, wherein the surface of the copper substrate is deposited on the silicon-based material by one of plasma enhanced chemical vapor deposition, hot filament chemical vapor deposition, high power pulsed magnetron sputtering, and chemical vapor deposition.
  6. 6. The method of claim 4, wherein the surface of the copper substrate is deposited on the carbon-based material by one of plasma enhanced chemical vapor deposition, hot filament chemical vapor deposition, high power pulsed magnetron sputtering, and chemical vapor deposition.
  7. 7. The method of claim 4, wherein the aluminum composite layer is formed on an aluminum-based material by one of magnetron sputtering, metal organic chemical vapor deposition, atomic layer deposition, and vapor deposition.
  8. 8. Use of a silicon-based copper negative electrode sheet according to any one of claims 1 to 3 or prepared by a preparation method according to any one of claims 4 to 7 in a battery.

Description

Silicon-based copper negative electrode plate and preparation method and application thereof Technical Field The invention relates to the technical field of battery cathodes, in particular to a silicon-based copper negative electrode plate and a preparation method and application thereof. Background In a lithium ion battery system, a negative electrode plate is one of core components for determining battery energy density. In the charge and discharge process, the negative electrode realizes energy storage and release through reversible lithium ion intercalation/deintercalation reaction. Silicon (Si) -based anode materials are considered to be critical in breaking through the bottleneck of the existing energy density due to their extremely high theoretical specific capacity (about 4200mAh/g, well beyond 372-mAh/g of conventional graphite). The current collector in the negative electrode plate is used as a conductive bridge between an active substance and an external circuit, and core requirements such as high conductivity, electrochemical stability, mechanical strength, interface compatibility and the like need to be met, wherein the copper foil is widely applied to the current collector due to the fact that the copper foil has high electrochemical inertia and high conductivity, ductility and mechanical strength in the working potential. The common negative electrode plate in the prior art mainly uses a current collector to load active substances, and the active paste is coated, dried and solidified on the current collector through a roll coating transfer type coating, a slit extrusion type coating and other coating modes. However, the preparation process is complex, the production efficiency is low due to the processes of mixing, coating, drying, rolling and the like of the active slurry, the bonding strength between the active slurry and a current collector is limited, and capacity fading caused by detachment easily occurs in the circulation process. It is therefore desirable to provide a solution to the above-mentioned problems. Disclosure of Invention The invention aims to provide a silicon-based copper negative electrode piece and a preparation method and application thereof, and the silicon-based copper negative electrode piece is formed by circularly depositing a silicon-carbon material in micropores on the surface of a porous copper foil and sealing the micropores by using an aluminum composite layer, so that the load capacity and the contact area of the copper foil to the silicon-carbon material can be improved, the stability of the silicon-carbon material on the surface of the copper foil can be improved, and the energy density and the cycle life of a battery can be effectively improved. In a first aspect, the invention provides a silicon-based copper negative electrode plate, which comprises a copper substrate, wherein at least one surface of the copper substrate is provided with a plurality of micropores, a silicon-carbon composite layer is deposited in the micropores, an aluminum composite layer is deposited on at least one surface of the copper substrate, the aluminum composite layer at least seals the openings of the micropores, and the silicon-carbon composite layer comprises a silicon base layer and a carbon base layer which are deposited in a circulating manner. According to the negative electrode plate, the silicon-carbon composite layer is deposited in the micropores of the copper substrate, so that the load capacity and the position stability of the silicon-carbon composite layer on the surface of the copper substrate can be effectively improved, the aluminum composite layer is used for sealing the silicon-carbon composite layer, the position stability of the silicon-carbon composite layer in the micropores can be improved, and meanwhile, the volume change of silicon in the charging and discharging processes is limited. Optionally, the pore diameter of the micropores is 1nm-400nm. Optionally, the density of the micropores on the surface of the copper substrate is 50000 micropores per cm 2 to 100000 micropores per cm 2. Optionally, the total pore volume of the microwells is 0.15cm 3-0.35cm3. Optionally, the thickness of the aluminum composite layer is 1nm-300nm. Optionally, the copper substrate has a thickness of 8 μm. Optionally, the silicon-based layer includes amorphous silicon or amorphous silicon oxide. Optionally, the silicon-based layer has a thickness of 0.1 μm to 1.2 μm. Optionally, the carbon-based layer has a thickness of 0.1 μm to 0.6 μm. Optionally, the cyclic deposition times of the silicon-based layer and the carbon-based layer are 1 to 3 times. Optionally, the silicon carbon composite layer has a thickness of 0.5 μm to 3.0 μm. Optionally, the aluminum composite layer is formed by composite deposition of aluminum oxide and aluminum fluoride. In a second aspect, the invention provides a preparation method of a silicon-based copper negative electrode plate, which comprises th