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CN-121992216-A - Online degassing method for launder for preparing aluminum foil blank of battery

CN121992216ACN 121992216 ACN121992216 ACN 121992216ACN-121992216-A

Abstract

The invention provides a launder online degassing method for preparing a battery aluminum foil blank, which comprises the steps of S1, melting an aluminum ingot at 650-700 ℃, adding a Y 2 O 3 、Er 2 O 3 and Sc 2 O 3 composite modifier, controlling the Fe/Si ratio in the aluminum ingot to be 1.0-1.05, S2, refining while applying electromagnetic stirring, S3, guiding refined aluminum liquid into the launder, flowing at a flow rate of 0.3-0.5 m/S, carrying out vacuum air suction in the launder, wherein the air suction frequency is 1-3 times/S, controlling the temperature gradient delta T between an inlet and an outlet of the launder to be 20-30 ℃, S4, carrying out cast rolling on the degassed aluminum liquid, wherein the cooling strength is more than or equal to 1500L/min, S5, carrying out cold rolling on the cast-rolled blank with a total reduction rate of 75-85%, carrying out intermediate annealing on the aluminum foil blank after cold rolling, and carrying out sectional annealing at a temperature of 450+/-3 ℃ for 2.5 hours, thereby remarkably improving the quality and reducing the production energy consumption of surface mechanics of aluminum foil.

Inventors

  • YAO HONGJUN
  • HE FAMING
  • ZHOU HAOSHENG
  • LI MENG
  • BAI ZHIFENG
  • SONG YUANHANG

Assignees

  • 内蒙古联晟新能源材料有限公司

Dates

Publication Date
20260508
Application Date
20251231

Claims (10)

  1. 1. An online degassing method for a launder for preparing a battery aluminum foil blank, which is characterized by comprising the following steps: S1, melting an aluminum ingot at 650-700 ℃, adding 0.02-0.05wt% of a Y 2 O 3 、Er 2 O 3 and Sc 2 O 3 composite modifier, wherein the mass ratio of Er 2 O 3 to Sc 2 O 3 is 1:0.5, and controlling the Fe/Si ratio in the aluminum ingot to be 1.0-1.05; S2, introducing argon with the purity of more than or equal to 99.999% at the temperature of 730-750 ℃ for refining, and simultaneously applying electromagnetic stirring, wherein the stirring intensity is 60-80%, the frequency is 2.5-3.0 Hz, and the refining time is 4-5 h; S3, introducing refined aluminum liquid into a launder with the length of 8-12 m and the width of 35-45 mm, flowing at the flow rate of 0.3-0.5 m/S, and performing vacuum air suction in the launder, wherein the air suction frequency is 1-3 times/S, and controlling the temperature gradient delta T between the inlet and the outlet of the launder to be 20-30 ℃; S4, casting and rolling the degassed aluminum liquid at a rolling speed of 0.4-0.6 m/min, wherein the cooling strength is more than or equal to 1500L/min; S5, cold rolling the cast-rolled blank with a total rolling reduction of 75-85%, wherein the single rolling reduction is less than or equal to 6%, and performing intermediate annealing at 440-460 ℃; S6, carrying out sectional annealing on the aluminum foil blank after cold rolling, wherein the annealing temperature is 450 ℃ plus or minus 3 ℃, and the heat preservation time is 2.5h.
  2. 2. The online degassing method for a launder for battery aluminum foil blank production according to claim 1, wherein the amount of the compound modifier added in S1 is 0.03wt% y 2 O 3 、0.01wt%Er 2 O 3 and 0.005wt% sc 2 O 3 .
  3. 3. The online degassing method for a launder for battery aluminum foil blank production according to claim 2, wherein the electromagnetic stirring intensity in S2 is 70%, the frequency is 2.8Hz, and the refining time is 4.5h.
  4. 4. A method of on-line degassing of a launder for use in the production of aluminium foil blanks for batteries according to claim 3, wherein the launder in S3 has a length of 10m, a width of 40mm, a vacuum pumping frequency of 2 times/sec, a launder inlet temperature of 710 ℃, an outlet temperature of 685 ℃ and a temperature gradient Δt of 25 ℃.
  5. 5. An in-line degassing method for a launder for cell aluminum foil blank production as claimed in claim 4 wherein the absolute pressure of the vacuum pump in S3 is 50Pa.
  6. 6. The online degassing method for a launder for battery aluminum foil blank production according to claim 5, wherein the rolling speed of the casting and rolling in S4 is 0.5m/min and the roll pressure is 120MPa.
  7. 7. The method for online degassing of a launder for battery aluminum foil blank production according to claim 6, wherein the total reduction of the cold rolling in S5 is 80%, divided into 3 passes of rolling, each pass reduction being 6%.
  8. 8. The online degassing method for a launder for battery aluminum foil blank production according to claim 7, wherein the step of step S6 specifically comprises the steps of heat-preserving at 250 ℃ for 0.5h in the first stage, heat-preserving at 450 ℃ for 1.5h in the second stage, and heat-preserving at 250 ℃ for 0.5h in the third stage.
  9. 9. The online degassing method for the launder for preparing the aluminum foil blank of the battery according to claim 1, further comprising S7, carrying out electrolytic cleaning on the annealed aluminum foil blank, wherein the cleaning solution is 50g/L NaOH solution at the temperature of 40 ℃, and then coating a polyethylene glycol film with the thickness of 0.5 μm on the surface of the aluminum foil.
  10. 10. The online degassing method of a launder for preparing an aluminum foil blank for a battery according to claim 1, wherein the hydrogen content of the aluminum foil blank is less than or equal to 0.08mL/100gAl, the tensile strength at a thickness of 12 μm is more than or equal to 150MPa, the elongation is more than or equal to 4.0%, and the grain size deviation is less than 5 μm.

Description

Online degassing method for launder for preparing aluminum foil blank of battery Technical Field The invention relates to a launder online degassing method for preparing a battery aluminum foil blank. Background With the rapid development of new energy automobiles and intelligent equipment, the lithium ion battery is used as a core energy storage component, and the requirements on energy density and safety of the lithium ion battery are continuously improved. Aluminum foil is used as a key current collector material of the lithium ion battery, and the performance of the aluminum foil directly influences the comprehensive performance of the battery. At present, the aluminum foil of the power battery is mainly prepared from 1060 alloy serving as a raw material through complex processes such as casting rolling, multi-pass cold rolling, homogenizing annealing, foil rolling and the like, and the technical field faces double challenges of improving the performance of the aluminum foil and reducing the production energy consumption. In the prior art, the aluminum foil preparation process mainly has the following problems that firstly, the traditional process is high in energy consumption and low in production efficiency, production cost is high due to multi-pass cold rolling and annealing processes, secondly, when the thickness of the aluminum foil is reduced to below 15 mu m, the mechanical property attenuation phenomenon is easy to occur, the tensile strength and the elongation are obviously reduced, the problems are mainly caused by internal air hole defects and uneven grains caused by incomplete aluminum liquid purification, and furthermore, in the prior art, the aluminum liquid degassing treatment is mainly carried out in a furnace refining mode, the degassing effect is limited, and the melt temperature gradient is difficult to accurately control, so that the tissue uniformity in the subsequent casting and rolling process is poor. In addition, the traditional process is not accurate enough in controlling the components of the aluminum liquid, and particularly the mechanical property and the surface quality of the aluminum foil can be seriously influenced by unbalanced Fe/Si ratio. Although the industry tries to improve by optimizing rolling process parameters or adding alloy elements, the problem of performance attenuation of the aluminum foil under the ultra-thinning condition is not solved fundamentally. Therefore, there is a need for a launder online degassing method for battery aluminum foil blank preparation that improves the mechanical properties of the aluminum foil, improves the surface quality and reduces the production energy consumption. Disclosure of Invention The invention aims to solve the defects in the prior art, and provides a launder online degassing method for preparing a battery aluminum foil blank, which can remarkably improve the mechanical property of an aluminum foil, improve the surface quality and reduce the production energy consumption, and the aim of the invention is realized in the following way: the invention provides a launder on-line degassing method for preparing a battery aluminum foil blank, which is characterized by comprising the following steps: S1, melting an aluminum ingot at 650-700 ℃, and adding 0.02-0.05wt% of a Y 2O3、Er2O3 and Sc 2O3 composite modifier, wherein the mass ratio of Er 2O3 to Sc 2O3 is 1:0.5, and the Fe/Si ratio in the aluminum ingot is controlled to be 1.0-1.05; the stage is a basic link of the whole preparation process, and aims to ensure accurate control of the aluminum liquid components and optimization of microstructure; the rare earth oxide Y 2O3、Er2O3、Sc2O3 in the composite modifier forms heterogeneous nucleation core in aluminum melt to promote grain refinement, and meanwhile, the elements can form stable compounds with impurity elements in the aluminum liquid to purify the melt, and meanwhile, the adverse effect on the aluminum foil performance when Fe and Si elements exist independently can be avoided by accurately controlling the Fe/Si ratio. S2, introducing argon with the purity of more than or equal to 99.999% at the temperature of 730-750 ℃ for refining, simultaneously applying electromagnetic stirring, wherein the stirring intensity is 60-80%, the frequency is 2.5-3.0 Hz, and the refining time is 4-5 h, the stage aims at further purifying the aluminum liquid to remove gas and nonmetallic inclusion therein, the electromagnetic stirring can promote the homogenization of the components of the melt and avoid local segregation, and the principle is that the high-purity argon forms bubbles in the aluminum liquid, and takes away hydrogen and inclusion in the melt through physical adsorption. The lorentz force generated by electromagnetic stirring can drive the melt to flow, so that component homogenization and temperature homogenization are promoted. S3, introducing refined aluminum liquid into a launder with the length of 8-12 m and the width