CN-122010108-A - Quick-charge graphite anode material, preparation method thereof and lithium ion battery

Abstract

The invention discloses a quick-charge graphite negative electrode material, a preparation method thereof and a lithium ion battery, and belongs to the technical field of lithium ion batteries. The preparation method comprises the steps of carrying out pore-forming treatment on graphite by adopting laser etching to obtain porous graphite, preparing a catalyst metal layer on the surface of the porous graphite by a vapor deposition method, annealing to obtain metal nano particles, growing carbon nano tubes in situ by the vapor deposition method, removing the metal nano particles, and then coating by a fast ion layer to obtain the fast-charging graphite anode material. The invention constructs a multi-stage structure with the functions of high-efficiency ion/electron transmission channel and interface lithium compensation, and obviously improves the quick charge performance, the first efficiency and the cycling stability of the battery assembled by materials.

Inventors

• SONG HE
• SU HANG
• JIA ZHILIN
• WANG FEI
• LU WEIQING
• MA ZHEZHE

Assignees

• 安徽得壹能源科技有限公司

Dates

Publication Date

20260512

Application Date

20260106

Claims (10)

1. 1. The preparation method of the quick-charging graphite anode material is characterized by comprising the following steps of: performing pore-forming treatment on the graphite by adopting laser etching to obtain porous graphite; preparing a catalyst metal layer on the surface of porous graphite by a vapor deposition method, and annealing to obtain metal nano particles; growing the carbon nano tube in situ by a vapor deposition method; And (5) removing the metal nano particles, and coating the metal nano particles by a fast ion layer to obtain the fast-charging graphite anode material.
2. 2. The method according to claim 1, wherein the graphite has a particle diameter D50 of 5 to 20 μm, the porous graphite has a porosity of 5 to 30%, and the pore diameter is 2 to 100nm.
3. 3. The method according to claim 1, wherein in the step of preparing the catalyst metal layer by vapor deposition, the thickness of the catalyst metal layer is 0.5 to 20nm, and the metal is one or more of nickel, cobalt and iron.
4. 4. The method according to claim 3, wherein in the step of preparing the catalyst metal layer by vapor deposition, atomic layer deposition is used for vapor deposition.
5. 5. The method according to claim 1, wherein the annealing temperature is 350 to 500 ℃ and the annealing time is 2 to 5 hours.
6. 6. The method according to claim 1, wherein in the step of growing the carbon nanotubes in situ by a vapor deposition method, the vapor deposition is chemical vapor deposition, and the mass of the grown carbon nanotubes is 0.4-2% of the mass of the porous graphite.
7. 7. The method of claim 1, wherein the metal nanoparticles are removed by physical grinding or chemical etching.
8. 8. The preparation method of claim 1, wherein the coating amount of the fast ion layer is 0.1-3% of the mass of the porous graphite, the fast ion layer is prepared by adopting an atomic layer deposition mode, and the fast ion layer is made of one or more of LiF, li 2 O or Li 3 P.
9. 9. The rapid graphite charging anode material is characterized by being prepared by the preparation method of any one of claims 1-8.
10. 10. A lithium ion battery comprising the fast-charging graphite anode material of claim 9.

Description

Quick-charge graphite anode material, preparation method thereof and lithium ion battery Technical Field The invention relates to the technical field of lithium ion batteries, in particular to a quick-charge graphite negative electrode material, a preparation method thereof and a lithium ion battery. Background The information disclosed in the background of the invention is only for enhancement of understanding of the general background of the invention and is not necessarily to be taken as an admission or any form of suggestion that this information forms the prior art already known to a person of ordinary skill in the art. Lithium ion batteries are currently one of the most important electrochemical energy storage systems, and their fast charging capability and energy efficiency have become key factors for restricting further development in the fields of electric automobiles, portable electronic devices and the like. Graphite cathode materials have been dominant in the market to date due to their cost and overall performance advantages. However, the inherent lamellar crystal structure causes slow kinetics of lithium ion intercalation/deintercalation, and when being charged by a large current, the lithium ion intercalation/deintercalation lithium ion battery not only can cause serious electrode polarization and capacity attenuation, but also has potential safety hazards such as lithium precipitation and the like. In order to improve the rapid charging performance, the construction of a porous structure to expand the ion transmission channel is an effective approach. However, the introduction of the porous structure improves the ion transmission capacity and simultaneously also puts higher demands on the conductive network and interface stability of the material. Currently, three-dimensional conductive networks are often constructed by introducing conductive agents such as carbon nanotubes to compensate for electron transport. However, it is difficult to achieve a firm and uniform ohmic contact in the graphite matrix, especially inside complex channels, by conventional physical mixing or solution impregnation catalytic growth methods. The carbon nanotubes introduced are easy to agglomerate or unevenly distributed, resulting in limited conductivity and efficiency. More serious, the method can introduce harmful impurities, such as halogen elements remained by certain catalyst precursors, which can obviously aggravate electrolyte decomposition and damage electrode interfaces, thereby not only increasing the internal resistance of the battery, but also becoming the hidden trouble of accelerating deterioration of performance in long-term circulation. Furthermore, the first coulombic inefficiency is another core bottleneck in constraining graphite cathodes, especially when matching high capacity positive electrode systems. The active lithium irreversibly consumed in the process of forming the solid electrolyte interface film directly reduces the energy density of the full cell. Although the pre-lithium supplementation technique has been widely studied, how to achieve accurate, uniform and compatible lithium compensation with existing electrode processes while avoiding the introduction of negative effects remains a serious challenge faced by the current techniques. Therefore, the existing modification strategy can only solve single problems of ion transmission, electronic conduction or lithium compensation, and the like, and is difficult to systematically overcome multiple challenges of high internal resistance, insufficient quick charge performance, low first efficiency, and the like, so that the prepared graphite material is difficult to consider in terms of comprehensive performance and long-term reliability. The development of a graphite negative electrode material capable of cooperatively optimizing ion/electron transmission and realizing efficient interface lithium compensation and a preparation method thereof has become a key bottleneck faced in the technical development of the current quick-charging battery. Disclosure of Invention In view of the above, the invention provides a fast-charging graphite anode material, a preparation method thereof and a lithium ion battery, the invention is cooperatively applied by laser etching and vapor deposition technology, the multi-stage structure with the functions of high-efficiency ion/electron transmission channels and interface lithium compensation is constructed, and the quick charge performance, the first efficiency and the cycling stability of the battery assembled by materials are remarkably improved. In a first aspect, the invention provides a preparation method of a fast-charging graphite anode material, which comprises the following steps: performing pore-forming treatment on the graphite by adopting laser etching to obtain porous graphite; preparing a catalyst metal layer on the surface of porous graphite by a vapor deposition method, and annealing to obtai