CN-122025662-A - Composite aluminum current collector, preparation method thereof, electrode plate, battery and power utilization device

CN122025662ACN 122025662 ACN122025662 ACN 122025662ACN-122025662-A

Abstract

The invention provides a composite aluminum current collector, a preparation method thereof, an electrode plate, a battery and an electric device, and particularly relates to the technical field of current collectors. The composite aluminum current collector comprises a macromolecule-based film, an organic-inorganic hybridization gradient transition layer and a metal aluminum layer which are sequentially stacked, wherein the organic-inorganic hybridization gradient transition layer comprises silicon, carbon, oxygen and hydrogen elements, and the content of the silicon, carbon, oxygen and hydrogen elements in the organic-inorganic hybridization gradient transition layer is gradually increased along the direction from the macromolecule-based film to the metal aluminum layer. The organic-inorganic hybrid gradient transition layer of the composite aluminum current collector provided by the invention fundamentally eliminates physical cliffs at the traditional double-layer interface, remarkably improves the interface bonding strength, inhibits the permeation and electrochemical corrosion of electrolyte, and enhances the high-temperature and cyclic stability, thereby synchronously solving the key technical bottlenecks of interface stripping failure, rate capability attenuation, poor high-voltage system compatibility and the like in the long-term service process of the composite current collector.

Inventors

Chu Guinan
LI GUOJUN
BU SHAONING
WU JUNWEI
WENG WEIJIA

Assignees

江苏英联复合集流体有限公司

Dates

Publication Date: 20260512
Application Date: 20260331

Claims (12)

1. The composite aluminum current collector is characterized by comprising a high polymer base film, an organic-inorganic hybridization gradient transition layer and a metal aluminum layer which are sequentially laminated; The organic-inorganic hybrid gradient transition layer comprises silicon, carbon, oxygen and hydrogen elements; Along the direction from the polymer-based film to the metal aluminum layer, the contents of silicon, carbon, oxygen and hydrogen elements in the organic-inorganic hybridization gradient transition layer all show an increasing trend.
2. The composite aluminum current collector according to claim 1, wherein the polymer-based film comprises at least one of polyethylene terephthalate, polypropylene, polyimide, or polyethylene naphthalate; and/or the thickness of the polymer base film is 2.0-8.0 μm, preferably 4.0-6.0 μm; And/or the thickness of the organic-inorganic hybridization gradient transition layer is 10-500 nm, preferably 50-200 nm; and/or the thickness of the metal aluminum layer is 0.5-3.0 μm, preferably 0.8-1.5 μm.
3. The composite aluminum current collector according to claim 1, wherein in the organic-inorganic hybrid gradient transition layer, along the direction from the polymer base film to the metal aluminum layer, the O/Si atomic ratio presents an increasing trend; And/or, at the interface adjacent to the polymer base film, the O/Si atomic ratio is 0.75 to 0.85; And/or the O/Si atomic ratio is 1.5-2.5 at the interface adjacent to the metal aluminum layer.
4. The composite aluminum current collector according to claim 1, wherein in the organic-inorganic hybrid gradient transition layer, the modulus of the organic-inorganic hybrid gradient transition layer tends to increase in the direction from the polymer base film to the metal aluminum layer; And/or, at the interface adjacent to the polymer base film, the modulus of the organic-inorganic hybrid gradient transition layer is 2-5 GPa; and/or, at the interface adjacent to the metal aluminum layer, the modulus of the organic-inorganic hybrid gradient transition layer is 60-80 GPa; And/or, in the organic-inorganic hybrid gradient transition layer, the refractive index of the organic-inorganic hybrid gradient transition layer is in a decreasing trend along the direction from the polymer base film to the metal aluminum layer; and/or, at the interface adjacent to the polymer base film, the refractive index of the organic-inorganic hybrid gradient transition layer is 1.54-1.56; and/or, at the interface adjacent to the metal aluminum layer, the refractive index of the organic-inorganic hybrid gradient transition layer is 1.47-1.49; And/or, in the organic-inorganic hybrid gradient transition layer, the density of the organic-inorganic hybrid gradient transition layer tends to increase in the direction from the polymer base film to the metal aluminum layer; And/or, at the interface adjacent to the polymer base film, the density of the organic-inorganic hybrid gradient transition layer is 1.4-1.6 g/cm 3 ; and/or, at the interface adjacent to the metal aluminum layer, the density of the organic-inorganic hybrid gradient transition layer is 2.0-2.4 g/cm 3 .
5. A preparation method of the composite aluminum current collector according to any one of claims 1-4 is characterized by comprising the steps of carrying out surface activation on a high polymer base film, then adopting a plasma enhanced chemical vapor deposition process to deposit an organic-inorganic hybrid gradient transition layer on the surface of the activated high polymer base film in situ, and finally preparing a metal aluminum layer on the organic-inorganic hybrid gradient transition layer by adopting a vacuum coating process to obtain the composite aluminum current collector.
6. The method according to claim 5, wherein when the polymer-based film is surface-activated by oxygen plasma or argon-oxygen mixed gas plasma, the treatment power is 100 to 500w, and the treatment time is 10 to 60 seconds; And/or carrying out the plasma enhanced chemical vapor deposition by using an organosilicon precursor as a raw material, wherein the carrier gas is argon; and/or the organosilicon precursor comprises hexamethyldisilazane or ethyl orthosilicate.
7. The preparation method according to claim 5, wherein the gradient change of the organic-inorganic hybrid gradient transition layer is realized by dynamically controlling deposition process parameters, specifically comprising the following steps: in the time T1, the oxygen flow Q 1 is 0-10 sccm, and the radio frequency power P 1 is 50-150W; In the T2 time, the oxygen flow is linearly or stepwise increased from Q 1 to Q 2 , the oxygen flow Q 2 is 30-80 sccm, meanwhile, the radio frequency power is linearly or stepwise increased from P 1 to P 2 , and the radio frequency power P 2 is 250-400W; during time T3, the oxygen flow is maintained at Q 2 and the rf power is maintained at P 2 .
8. The method according to claim 7, wherein T1 is 0 to 30s; and/or, T2 is 30-90 s; and/or, T3 is 90-120 s.
9. The preparation method of any one of claims 5 to 8, wherein the deposition process of the metal aluminum layer comprises the steps of depositing an aluminum seed layer on the organic-inorganic hybrid gradient transition layer under an inert atmosphere by using a magnetron sputtering method and taking metal aluminum as a target material, and then preparing the metal aluminum layer by adopting a vacuum evaporation method; And/or, the preparation method further comprises an annealing step after forming the metallic aluminum layer, The annealing step is carried out in vacuum or inert atmosphere, the annealing temperature is 80-180 ℃, and the annealing time is 0.5-4 h; preferably, the thickness of the aluminum seed layer is 20-100 nm.
10. An electrode sheet characterized by comprising the composite aluminum current collector according to any one of claims 1 to 4 or the composite aluminum current collector prepared by the preparation method according to any one of claims 5 to 9.
11. A battery comprising the electrode sheet of claim 10.
12. An electrical device comprising the battery of claim 11.

Description

Composite aluminum current collector, preparation method thereof, electrode plate, battery and power utilization device Technical Field The invention relates to the technical field of current collectors, in particular to a composite aluminum current collector, a preparation method thereof, an electrode plate, a battery and an electric device. Background The lithium ion battery composite current collector generally adopts a double-layer structure of combining a polymer base film and a metal conducting layer, wherein the polymer base film provides light weight advantages and gives a fusing safety mechanism, and the metal layer plays a role in electronic conduction. In order to achieve the combination of the two, the prior art generally adopts a direct sputtering or vapor deposition mode to deposit a metal layer on the surface of the activated base film, or introduces a non-gradient single layered transition layer (such as Ti, cr, znO inorganic intermediate layers) so as to improve wettability and initial adhesion. Such structures have been applied in the partial mass production of composite aluminum foils, constituting the current industry mainstream technology path. However, the technical route has the fundamental interface compatibility defect that the modulus of the high molecular base film is 2-4 GPa, the high molecular base film is rich in organic bonds such as C-H, C =O, the modulus of the metal aluminum layer is about 70 GPa, the metal bonds are dominant, the high molecular base film of the composite aluminum current collector has severe mutation on the lattice structure, the thermal expansion coefficient, the Young modulus and the chemical bonding type of the high molecular base film and the metal aluminum layer, so that the direct contact interface of the high molecular base film and the metal aluminum layer can only form weak Van der Waals force or mechanical occlusion, and a stable covalent/coordination bonding network cannot be constructed, thereby causing the problem of significant concentration of internal stress of the interface, and seriously affecting the electrical performance and the safety performance of the battery. In view of this, the present invention has been made. Disclosure of Invention The invention aims to provide a composite aluminum current collector, a preparation method thereof and an electrode plate, and aims to solve the problem of concentration of internal stress of an interface between a high polymer-based film and a metal aluminum layer in the technical problems. In order to achieve the above object of the present invention, the following technical solutions are specifically adopted: The invention provides a composite aluminum current collector, which comprises a macromolecule based film, an organic-inorganic hybridization gradient transition layer and a metal aluminum layer which are sequentially stacked, wherein the organic-inorganic hybridization gradient transition layer comprises silicon (Si), carbon (C), oxygen (O) and hydrogen (H), and the contents of the silicon, the carbon, the oxygen and the hydrogen in the organic-inorganic hybridization gradient transition layer all show an increasing trend along the direction from the macromolecule based film to the metal aluminum layer. Further, the polymer-based film may be at least one of polyethylene terephthalate (PET), polypropylene (PP), polyimide (PI) and polyethylene naphthalate (PEN). And/or the thickness of the polymer base film is 2.0-8.0 μm, preferably 4.0-6.0 μm. And/or the thickness of the organic-inorganic hybridization gradient transition layer is 10-500 nm, preferably 50-200 nm. And/or the thickness of the metal aluminum layer is 0.5-3.0 μm, preferably 0.8-1.5 μm. Further, in the organic-inorganic hybrid gradient transition layer, the O/Si atomic ratio tends to increase along the direction from the polymer base film to the metal aluminum layer. And/or, at the interface adjacent to the polymer base film, the O/Si atomic ratio is 0.75 to 0.85. And/or the O/Si atomic ratio is 1.5-2.5 at the interface adjacent to the metal aluminum layer. Further, in the organic-inorganic hybrid gradient transition layer, the modulus of the organic-inorganic hybrid gradient transition layer tends to increase along the direction from the polymer base film to the metal aluminum layer. And/or the modulus of the organic-inorganic hybrid gradient transition layer is 2-5 GPa at the interface adjacent to the polymer base film. And/or the modulus of the organic-inorganic hybrid gradient transition layer is 60-80 GPa at the interface adjacent to the metal aluminum layer. And/or, in the organic-inorganic hybrid gradient transition layer, the refractive index of the organic-inorganic hybrid gradient transition layer is in a decreasing trend along the direction from the polymer base film to the metal aluminum layer. And/or the refractive index of the organic-inorganic hybridization gradient transition layer is 1.54-1.56 at the interface adj