Laser-induced fluorine-doped lithium metal battery negative electrode material and preparation method thereof
The array of negative electrode materials of lithium metal battery is prepared by laser-induced fluorine doping method, which solves the problem that traditional lithium-ion battery materials are difficult to meet the needs of high energy density and long cycle life, and achieves excellent electrochemical performance and stability of lithium metal batteries.
Patent Information
- Application Number
- CN202510277126.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-10
- Publication Date
- 2025-06-06
AI Technical Summary
Traditional lithium-ion battery negative electrode materials are difficult to meet the needs of higher energy density and longer cycle life. Li metal batteries have low Coulomb efficiency and safety problems due to the formation of lithium dendrites.
By using a laser-induced fluorine doping method, a array of fluorine-doped lithium metal battery negative electrode materials are formed by applying a polytetrafluoroethylene film onto a copper foil and laser treatment.
It improves the electrochemical performance and cyclic stability of lithium metal batteries, reduces the nucleation overpotential, enhances the rate performance, and simplifies the preparation process.
Smart Images
Figure CN120109202A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of lithium metal batteries, and in particular relates to a laser-induced fluorine-doped lithium metal battery negative electrode material and a preparation method thereof. Background Art
[0002] With the continuous development of new energy technologies, lithium-ion batteries, as key devices for energy storage and conversion, play an increasingly important role in electric vehicles, portable electronic devices, and large-scale grid energy storage. However, traditional lithium-ion battery anode materials, such as graphite, despite their relatively stable electrochemical properties and high energy density, still cannot meet the growing demand for higher energy density and longer cycle life.
[0003] Lithium metal, due to its extremely high theoretical specific capacity (3860 mAh / g), is regarded as an ideal candidate for the anode material of next-generation high-energy-density lithium-ion batteries. However, uncontrolled lithium dendrite formation during electrochemical deposition leads to low Coulombic efficiency and serious safety issues. Unfortunately, the practical application of lithium metal batteries (LMBs) is severely hindered by the reactivity, large changes in Li, and uncontrolled dendrite growth. Many efforts have been made to improve the stability of lithium metal anodes (LMAs), including by modifying liquid electrolytes, constructing artificial solid electrolyte interface (SEI) layers, adopting solid-state electrolytes, and designing three-dimensional (3D) porous lithium hosts.
[0004] However, although fluorine doping and laser induction methods have made certain progress in their respective fields, there are relatively few studies on combining the two to prepare fluorine-doped lithium metal battery negative electrode materials. Therefore, the present invention proposes a laser-induced fluorine-doped lithium metal battery negative electrode material and a preparation method thereof, aiming to combine the advantages of fluorine doping and laser induction methods to prepare a lithium metal negative electrode material with excellent electrochemical performance and cycle stability. Summary of the invention
[0005] The present invention proposes a simple and scalable method for stabilizing lithium metal anodes using laser technology, specifically involving the preparation and application of laser-induced fluorine-doped lithium metal battery negative electrode materials.
[0006] The present invention attaches a polytetrafluoroethylene (PTFE) film to a copper foil, performs laser processing on the polymer film, forms a fluorine-doped lithium metal battery negative electrode material by laser induction, and finally forms a fluorine-doped array. The method for preparing fluorine-doped lithium metal negative electrode material of the present invention is simple, and a fluorine-doped array can be generated in one step at normal temperature, pressure and ambient atmosphere; at the same time, the array can be used as a host material for the negative electrode of a lithium metal battery, so that the prepared lithium metal battery has the advantages of low nucleation overpotential, good cycle stability, excellent rate performance, etc.
[0007] To achieve the above purpose, the technical solution adopted by the present invention is as follows:
[0008] A method for preparing a laser-induced fluorine-doped lithium metal battery negative electrode material comprises the following steps:
[0009] Step 1: Attach polytetrafluoroethylene (PTFE) tape to copper foil, and fix the two together through the adhesiveness of the tape to form a PTFE-copper foil current collector;
[0010] Step 2: The current collector is directly laser treated as the negative electrode material for lithium metal batteries.
[0011] Preferably, the method further comprises step three: removing the polytetrafluoroethylene tape from the copper foil, washing it with anhydrous ethanol and ultrapure water in sequence, and using FC@Cu as the negative electrode of a lithium metal battery.
[0012] Preferably, in step 2, the current collector substrate is scanned with a pulsed laser for 4 cycles.
[0013] Preferably, step one further comprises covering the copper foil current collector evenly on the glass plate and washing it with anhydrous ethanol, and then sticking polytetrafluoroethylene on the copper foil and wiping it with anhydrous ethanol.
[0014] Preferably, step 2 is carried out under air atmosphere.
[0015] Preferably, the copper foil current collector has a thickness of 0.02 mm to 0.04 mm.
[0016] Preferably, the thickness of the polytetrafluoroethylene (PTFE) membrane is 0.08 mm-0.13 mm.
[0017] Preferably, in step 2, the laser scribing uses a YAG laser with a fixed wavelength of 106 nm.
[0018] Preferably, the process parameters of the laser scribing are: spot size is 0.050mm-0.10mm, scanning speed is 250-500mm·s -1 , frequency 10-25KHz, line spacing: 0.01mm-0.03mm, height 11.4cm-12.00cm, power 40W%-55W%.
[0019] Compared with the prior art, the present invention has the following beneficial effects:
[0020] The present invention discloses a method for preparing a laser-induced fluorine-doped copper-lithium metal battery negative electrode material. First, a layer of polytetrafluoroethylene (PTFE) film is attached to the surface of copper foil, and then the current collector is directly laser-treated to form a fluorine-doped carbon copper foil array by laser induction. The present invention irradiates the material with laser one to four times, and obtains that the F doping after four laser irradiations is more uniform. The present invention is used to dope fluorine to form an FC@Cu array. Figure 3 The FC@Cu SEM structure diagram is shown in Figure 1. The FC@Cu array can be used as the host material for the negative electrode of lithium metal batteries, where a good current path is formed between FC and copper foil, F has lithium affinity, and the CF semi-ionic bond can also adsorb lithium ions, which not only reduces the nucleation overpotential of metallic lithium, but also helps to induce uniform deposition of metallic lithium and dendrite-free growth, further improving the electrochemical performance of lithium metal batteries. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 Schematic diagram of the contact angle structure of pure copper foil;
[0022] Figure 2 Schematic diagram of the contact angle structure of FC@Cu;
[0023] Figure 3 Schematic diagram of the FC@Cu scanning electron microscope structure. DETAILED DESCRIPTION
[0024] The present invention is described in detail below in conjunction with specific examples, which should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics and embodiments of the present invention. Unless otherwise specified, the experimental equipment, materials, reagents, etc. used in the present invention can be obtained from commercial sources.
[0025] Example 1
[0026] Step 1: Cover the glass plate evenly with a copper foil current collector with a thickness of 0.004 mm and an area of 10 cm × 10 cm, and wash it with anhydrous ethanol. Then stick polytetrafluoroethylene with a thickness of 0.08 mm and an area of 10 cm × 10 cm on the copper foil and wipe it with anhydrous ethanol.
[0027] Step 2: In air atmosphere, the surface was laser processed for the first time using a commercial YAG laser engraver with a wavelength of 1064nm. The processing area was a 12cm×12cm square. The PTFE film was scribed row by row in the processing area. The fixed spot size was 0.050mm, the frequency was 20KHz, the line spacing was 0.01mm, the focal length of the galvanometer was 11.6mm, the scanning speed was 500mm / s, and the average power was 20W. The substrate was scanned with a pulsed laser for 4 cycles.
[0028] Step 3: Remove the polytetrafluoroethylene tape from the copper foil, wash it with anhydrous ethanol and ultrapure water in turn, use FC@Cu as the negative electrode of the lithium metal battery, and conduct electrochemical performance tests.
[0029] Electrochemical tests: To evaluate the reversibility of lithium deposition and stripping, FC@Cu and Cu foil were assembled with Li as half-cells, Cu|Li and FC@Cu|Li half-cells, respectively, at 1 mA cm -2 The current and area are 1 mAh cm -2 Under the condition of FC@Cu, after 150h of cycling, the coulombic efficiency of FC@Cu is still 96%, while that of Cu|Li drops to 68% after 20h of cycling, indicating that the battery performance continues to decline and begins to fail.
[0030] Comparative Example 1 Preparation of Laser-Induced FC@Cu Array
[0031] Step 1: Cover the glass plate evenly with a copper foil current collector with a thickness of 0.004mm and an area of 10cm×10cm, and wash it with anhydrous ethanol. Then stick a polytetrafluoroethylene tape with a thickness of 0.08mm and an area of 10cm×10cm on the copper foil and wipe it with anhydrous ethanol.
[0032] Step 2: In air atmosphere, the surface was laser processed for the first time using a commercial YAG laser engraver with a wavelength of 1064 nm. The processing area was a 12 cm × 12 cm square. The PTFE film was scribed row by row and column by column in the processing area. The fixed spot size was 0.050 mm, the frequency was 20 KHz, the line spacing was 0.01 mm, and the focal length of the galvanometer was 11.6 mm. Compared with the example, the scanning speed and power were changed, with a scanning speed of 250 mm / s and an average power of 30 W. The substrate was scanned with a pulsed laser for 4 cycles.
[0033] Step 3: Remove the polytetrafluoroethylene tape from the copper foil, wash it with anhydrous ethanol and ultrapure water in turn, cut the FC@Cu array in the embodiment and the display of the comparative example into circular pole pieces with a diameter of 12 mm, and use them as negative electrode host materials for lithium metal batteries for electrochemical performance testing.
[0034] In summary, the present invention uses nanosecond pulse laser to directly induce PTFE to generate fluorine-doped C (FC), and uses copper foil as a carrier fluid. The prepared FC@Cu array can be used as a host material for the negative electrode of a lithium metal battery. Figure 1The contact angle of pure copper is as high as 35°, while the contact angle of FC@Cu is only 12.5°, indicating that the material has greatly improved the wettability of the electrolyte layer. The lithium metal battery prepared with FC@Cu array as electrode has the advantages of low nucleation overpotential, good cycle stability, and excellent rate performance. Moreover, the laser method of the present invention for preparing fluorine-doped graphene is simple and can be completed in one step at room temperature and pressure in ambient atmosphere, which is conducive to large-scale promotion and application.
[0035] The above-described embodiments are only preferred embodiments of the present invention, but not all feasible embodiments of the present invention. For those skilled in the art, any obvious changes made thereto without departing from the principles and spirit of the present invention should be considered to be included in the scope of protection of the claims of the present invention.
Claims
1. A method for preparing a laser-induced fluorine-doped lithium metal battery negative electrode material, characterized in that: The following steps are involved: Step 1: Attach polytetrafluoroethylene (PTFE) tape to copper foil, and fix the two together through the adhesiveness of the tape to form a PTFE-copper foil current collector; Step 2: The current collector is directly laser treated as the negative electrode material for lithium metal batteries.
2. The method for preparing the laser-induced fluorine-doped lithium metal battery negative electrode material according to claim 1, characterized in that: It also includes step three: removing the polytetrafluoroethylene tape from the copper foil, washing it with anhydrous ethanol and ultrapure water in sequence, and using FC@Cu for the negative electrode of the lithium metal battery.
3. The method for preparing the laser-induced fluorine-doped lithium metal battery negative electrode material according to claim 1, characterized in that: In step 2, the current collector substrate is scanned with a pulsed laser for 4 cycles.
4. The method for preparing the laser-induced fluorine-doped lithium metal battery negative electrode material according to claim 1, characterized in that: Step one also includes flatly covering the glass plate with the copper foil current collector and washing it with anhydrous ethanol, and then sticking polytetrafluoroethylene on the copper foil and wiping it with anhydrous ethanol.
5. The method for preparing the laser-induced fluorine-doped lithium metal battery negative electrode material according to claim 1, characterized in that: Step 2 can be carried out under air atmosphere.
6. The method for preparing the laser-induced fluorine-doped lithium metal battery negative electrode material according to claim 1, characterized in that: The thickness of the copper foil current collector is 0.02 mm-0.04 mm.
7. The method for preparing the laser-induced fluorine-doped lithium metal battery negative electrode material according to claim 1, characterized in that: The thickness of the polytetrafluoroethylene (PTFE) film is 0.08 mm to 0.13 mm.
8. The method for preparing the laser-induced fluorine-doped lithium metal battery negative electrode material according to claim 1, characterized in that: In step 2, the laser scribing uses a YAG laser with a fixed wavelength of 106 nm.
9. The method for preparing the laser-induced fluorine-doped lithium metal battery negative electrode material according to claim 1, characterized in that: The process parameters of the laser scribing are: spot size is 0.050mm-0.10mm, scanning speed is 250-500mm·s -1 , frequency 10-25KHz, line spacing: 0.01mm-0.03mm, height 11.4cm-12.00cm, power 40W%-55W%.
10. A laser-induced fluorine-doped lithium metal battery negative electrode material, characterized in that: It is prepared according to the preparation method according to any one of claims 1 to 9.