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CN-121992254-A - Steel-aluminum composite board for battery pack and preparation method thereof

CN121992254ACN 121992254 ACN121992254 ACN 121992254ACN-121992254-A

Abstract

The invention relates to the technical field of steel-aluminum composite plates, in particular to a steel-aluminum composite plate for a battery pack and a preparation method thereof, and the steel-aluminum composite plate comprises the following steps of (S1) pretreatment, polishing and cleaning the surfaces to be composited of a steel plate and an aluminum plate respectively, (S2) assembly, stacking the steel plate and the aluminum plate treated in the step (1) according to the sequence of the aluminum plate, the steel plate and the aluminum plate, (S3) rolling, rolling and forming the original plate blank obtained in the step (2), and (S4) annealing, and performing diffusion annealing treatment on the composite plate obtained in the step. The invention relates to a steel-aluminum composite board for a battery pack and a preparation method thereof, which have light weight, high strength and excellent corrosion resistance.

Inventors

  • LIU SHUANG
  • WANG HANCHAO
  • DONG WEIWEI

Assignees

  • 烟台力华电源科技有限公司

Dates

Publication Date
20260508
Application Date
20260204

Claims (8)

  1. 1. The steel-aluminum composite board for the battery pack is characterized by comprising an aluminum plate and a steel plate which are mutually rolled, wherein the aluminum plate is respectively arranged at two sides of the steel plate; the aluminum plate comprises the following components, by mass, less than or equal to 0.25% of Si, less than or equal to 3.00% of Mn, less than or equal to 0.35% of Fe, less than or equal to 0.05% of Cu, less than or equal to 0.03% of Mg, less than or equal to 0.05% of Zn, less than or equal to 0.03% of Ti, and the balance of Al; The steel plate comprises the following components, by mass, less than or equal to 0.08% of C, less than or equal to 2.00% of Mn, less than or equal to 1.00% of Si, less than or equal to 0.045% of P, less than or equal to 0.030% of S, 18.00% -20.00% of Cr, 8.00% -10.50% of Ni and the balance of Fe.
  2. 2. A process for preparing the steel-aluminum composite board for battery packs as claimed in claim 1, which is characterized by comprising the following steps: (S1) preprocessing, namely polishing and cleaning the surfaces to be compounded of the steel plate and the aluminum plate respectively; (S2) assembling, namely stacking the steel plate and the aluminum plate treated in the step (1) in the sequence of the aluminum plate, the steel plate and the aluminum plate; (S3) rolling, namely rolling and forming the original slab obtained in the step (2); and (S4) annealing, wherein the composite board prepared by the steps is subjected to diffusion annealing treatment.
  3. 3. The process for producing a steel-aluminum composite panel for battery packs according to claim 2, wherein the steel sheet and the aluminum sheet selected in the step (S1) are both annealed steel sheet and aluminum sheet, wherein the thickness of the steel sheet is 0.5 to 2mm and the thickness of the aluminum sheet is 1 to 2mm.
  4. 4. The process for preparing a steel-aluminum composite panel for a battery pack according to claim 2, wherein in the step (S1), the steel plate is treated by a metal wire drawing process, the aluminum plate is polished by a belt sander, and then the treated steel plate and aluminum plate are washed by absolute ethyl alcohol.
  5. 5. The process for producing a steel-aluminum composite panel for a battery pack according to claim 2, wherein after the completion of step (S2), a caulking process is perforated at the edges of the stacked steel plates and aluminum plates.
  6. 6. The process for producing a steel-aluminum composite panel for battery packs according to claim 2, wherein the rolling temperature in step (S3) is cold rolling or hot rolling.
  7. 7. The process for preparing the steel-aluminum composite board for the battery pack according to claim 6, wherein the hot rolling temperature in the step (S3) is 350-450 ℃, the heat preservation time in the hot rolling is 5-10 min, the rolling reduction is 50-60%, and the rolling speed is 1-2 m/S.
  8. 8. The process for preparing the steel-aluminum composite board for the battery pack according to claim 2, wherein the annealing temperature in the step (S4) is 400-500 ℃ and the heat preservation time is 1-2 h.

Description

Steel-aluminum composite board for battery pack and preparation method thereof Technical Field The invention relates to the technical field of steel-aluminum composite boards, in particular to a steel-aluminum composite board for battery packs and a preparation method thereof. Background In the structural design of battery packs (especially power battery packs for new energy vehicles), light weight and high strength are core requirements. The traditional battery pack shell adopts a pure aluminum plate or a pure steel plate, wherein the pure aluminum plate has the advantages of light weight (low density) but insufficient strength, the structural stability requirements of the battery pack under the working conditions of collision, vibration and the like are difficult to meet, and the pure steel plate has high strength but large weight, so that the energy consumption of the whole vehicle is increased, and the endurance mileage is shortened. In addition, the battery pack has a complex working environment, corrosion resistance (such as dealing with humid and salt fog environments) and thermal management performance (such as heat dissipation requirements) are required to be considered, and a single metal material is difficult to simultaneously meet multiple performance indexes. In the prior art, the steel-aluminum composite board combines two metals through rolling, so that the weight and the strength can be balanced, but the following technical bottlenecks exist: (1) The interface bonding strength is insufficient, the difference of the thermal expansion coefficients of steel and aluminum is large, and interface stress is easy to generate in the rolling process, so that a bonding layer is peeled off or cracked, and the sealability of the battery pack is affected. (2) Embrittlement of intermetallic compound, namely that elements such as Cr and Ni in steel and impurities such as Si and Fe in aluminum are easy to form brittle phases (such as Fe-Al intermetallic compound) during high-temperature rolling, so that the toughness of the composite board is reduced. (3) The process compatibility is poor, the traditional rolling process is not optimized for the steel-aluminum composite plate for the battery pack, so that the interface bonding is uneven, and the subsequent stamping forming precision is affected. Based on this, improvement of the case of the battery pack is required. Disclosure of Invention In order to overcome the defects in the prior art, the invention provides a steel-aluminum composite board for a battery pack and a preparation method thereof. The invention aims to provide a steel-aluminum composite board for a battery pack, which comprises an aluminum plate and a steel plate which are mutually rolled, wherein the aluminum plate is respectively arranged at two sides of the steel plate; the aluminum plate comprises the following components, by mass, less than or equal to 0.25% of Si, less than or equal to 3.00% of Mn, less than or equal to 0.35% of Fe, less than or equal to 0.05% of Cu, less than or equal to 0.03% of Mg, less than or equal to 0.05% of Zn, less than or equal to 0.03% of Ti, and the balance of Al; The steel plate comprises the following components, by mass, less than or equal to 0.08% of C, less than or equal to 2.00% of Mn, less than or equal to 1.00% of Si, less than or equal to 0.045% of P, less than or equal to 0.030% of S, 18.00% -20.00% of Cr, 8.00% -10.50% of Ni and the balance of Fe. The second purpose of the invention is to provide a preparation method of the battery steel-clad aluminum composite board, which comprises the following steps: (S1) preprocessing, namely polishing and cleaning the surfaces to be compounded of the steel plate and the aluminum plate respectively; (S2) assembling, namely stacking the steel plate and the aluminum plate treated in the step (1) in the sequence of the aluminum plate, the steel plate and the aluminum plate; (S3) rolling, namely rolling and forming the original slab obtained in the step (2); and (S4) annealing, wherein the composite board prepared by the steps is subjected to diffusion annealing treatment. Preferably, the steel sheet and the aluminum sheet selected in the step (S1) are both annealed steel sheet and aluminum sheet, wherein the thickness of the steel sheet is 0.5-2mm and the thickness of the aluminum sheet is 1-2mm. Preferably, in the step (S1), the steel plate is treated by a metal wire drawing process, the aluminum plate is polished by a belt sander, and then the treated steel plate and aluminum plate are cleaned by absolute ethyl alcohol. Preferably, after the step (S2) is completed, a caulking process is perforated at the edges of the stacked steel and aluminum plates. Preferably, the rolling temperature in step (S3) is cold rolling or hot rolling. The invention has the following technical effects: (1) Light weight and high strength synergy The aluminum plate adopts a high-purity design (Al is more than or equal to 99.6 percent