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CN-121976147-A - Copper foil synchronous roughening and lithiation treatment method

CN121976147ACN 121976147 ACN121976147 ACN 121976147ACN-121976147-A

Abstract

The invention relates to a copper foil synchronous roughening and lithiation treatment method, which comprises the following steps of placing a copper foil in a reaction chamber of an oxygen-containing atmosphere with an oxygen volume fraction of 20-100%, and carrying out heat treatment for 10-600 seconds at a temperature of 150-350 ℃ to form the surface with a copper nodule structure and a metal oxide lithiation layer in one step. The invention realizes dual-function integration through the oxidation reaction-thermal stress coupling effect, reduces equipment cost, reduces energy consumption, improves production efficiency and realizes zero wastewater discharge.

Inventors

  • LIANG YAOHUA
  • YUAN CHUPING
  • CHEN YAQIN
  • YANG HONGGUANG

Assignees

  • 九江德福科技股份有限公司

Dates

Publication Date
20260505
Application Date
20260109

Claims (8)

  1. 1. A method for synchronously roughening and lithiating copper foil is characterized by comprising the following steps of placing the copper foil in a reaction chamber of an oxygen-containing atmosphere with an oxygen volume fraction of 20% -100%, and carrying out heat treatment for 10-600 seconds at a temperature of 150-350 ℃ to form the surface of a copper nodule structure and a metal oxide lithiation layer in one step.
  2. 2. The method for simultaneous roughening and lithiation of a copper foil according to claim 1, wherein the balance of the oxygen-containing atmosphere is an inert gas.
  3. 3. The method for simultaneous roughening and lithiation of a copper foil according to claim 1, wherein the oxygen-containing atmosphere flow rate is controlled in the range of 10 to 200 sccm.
  4. 4. The method for simultaneous roughening and lithiation of copper foil according to claim 1, wherein the copper nodule structure morphology is pyramid-shaped, block-shaped or hemispherical, and the size is 0.2-5 μm.
  5. 5. The method for simultaneous roughening and lithiation of copper foil according to claim 1, wherein the metal oxide is CuO and/or Cu 2 O and the metal oxide lithiation layer has a thickness of 100-800: 800 nm.
  6. 6. A copper foil obtained by the method for simultaneous roughening and lithiation treatment of a copper foil according to claim 1.
  7. 7. A negative electrode for a lithium metal battery comprising the copper foil of claim 6 as a current collector.
  8. 8. A lithium metal battery comprising the lithium metal battery anode of claim 7.

Description

Copper foil synchronous roughening and lithiation treatment method Technical Field The invention belongs to the technical field of electrolytic copper foil, and particularly relates to a copper foil synchronous roughening and lithiation treatment method. Background The theoretical energy density of the lithium metal battery can reach more than 2 times of that of the existing lithium ion battery (breakthrough 500 Wh/kg), and the lithium metal battery is recognized as the core direction of the next-generation energy storage technology. Lithium metal as the negative electrode active material has two major irreplaceable advantages of an ultra-high specific capacity (mAh/g, 10 times that of graphite) and a minimum electrochemical potential (-3.04V vs. SHE). However, its commercialization process has long been limited by two key scientific problems: 1. Lithium dendrites grow uncontrollably, in which lithium tends to preferentially deposit at localized protrusions during cyclic charge and discharge due to uneven electric field distribution and ion concentration gradients at the electrode surface, forming dendrites or mossy dendrites. These dendrites not only penetrate the separator to cause internal short circuits (dendrite-induced battery failure is 73% of safety accidents), but also fracture to form "dead lithium" causing irreversible loss of active material. 2. Interfacial dynamic instability, a volume change accompanying up to 300% during lithium deposition/exfoliation, results in repeated cracking and regeneration of the solid electrolyte interfacial film (SEI). This process continues to consume electrolyte and active lithium, rapidly decaying the coulombic efficiency of the cell (CE <85% after 100 typical cycles), severely limiting cycle life. Current collector engineering is a core break-through to solve the above-mentioned problems. Electrolytic copper foil is currently commonly used as a negative electrode current collector (thickness of 6-12 μm) in commercial lithium ion batteries, but the intrinsic characteristics of the current collector expose serious defects in a lithium metal system: 1. Surface smoothness industrial copper foil surface roughness Rz is typically less than 1.2 μm, resulting in sparse lithium nucleation sites. Experiments show that the lithium nucleation overpotential of the original copper foil is as high as 110-140 mV (0.5 mA/cm < 2 >), and the lithium is induced to preferentially explode and grow at a few sites; 2. Intrinsic lithium repellency-copper contacts liquid lithium by a contact angle >90 °, interfacial energy barriers hinder lateral diffusion of lithium ions, deposition tends to form a loose porous structure, exacerbating dendrite risk. To overcome these drawbacks, the prior art generally employs a multi-step compounding process to modify the copper foil: 1. surface roughening treatment: And (3) adopting FeCl 3/H2SO4 or H 2O2/H2SO4 mixed solution to corrode the copper surface to form the micron-sized pits. Although the roughness Rz can be raised to 2-3 mu m, the acid waste liquid containing high-concentration Cu2 + (> 5000 ppm) is generated, and 50 tons of wastewater treatment facilities are matched for each 1 ton of copper foil; And the electrodeposition method is to construct a copper nano cone array in a copper sulfate electrolyte through pulse electroplating. Although the method can accurately control the morphology, the energy consumption is as high as 8-12 kWh/m < 2 >, and a cyanide complexing agent is needed, so that the method has environmental risks. 2. And (3) construction of a lithium-philic layer: Vacuum coating, namely depositing lithium-philic metals such as Zn, ag, au and the like (thickness is 100-500 nm) by magnetron sputtering, wherein equipment investment is over 2000 ten thousand yuan (calculated by a production line with a width of 1 m), and the deposition rate is only 0.5-2 m/min; Electroless plating, namely, ni-P or Sn-Bi alloy is reduced under the catalysis of Pd activating layer. The process involves formaldehyde reducing agent and heavy metal ion, and environmental pollution exists. The step-by-step process has three technical bottlenecks: ① The process complexity is high, independent working procedures are needed for coarsening and lithiation, and a cleaning and drying link is added in the middle, so that the production beat is prolonged by more than 3 times; ② And the interface bonding is weak, namely the post-deposition lithium-philic layer is physically bonded with the matrix, and the peeling strength is small. Under the volume stress of lithium deposition, large-area flaking occurs after 50 cycles; ③ The comprehensive cost is disadvantageous in that the two-step method increases the manufacturing cost of the copper foil by 35-40%, wherein the waste water treatment accounts for 15% and the depreciation of vacuum equipment accounts for 20%. Therefore, developing a high-efficiency, environment-friendly and low-cost one-step process to realize the