What are the advantages of laser cutting for lithium battery pole pieces?
Both disc slitting and die cutting have tool wear problems, which easily cause process instability, lead to poor cutting quality of pole pieces, and reduce battery performance. Laser cutting has the characteristics of high production efficiency and good process stability. It has been used in the cutting of lithium-ion battery pole pieces in industry. The basic principle is to use high-power density laser beams to irradiate the cut battery pole pieces to make the pole pieces It is quickly heated to a very high temperature, quickly melted, vaporized, ablated or reached the ignition point to form a hole. As the beam moves on the pole piece, the hole continuously forms a narrow slit to complete the cutting of the pole piece.（Cutting and stacking Integrated machine）
Since the pole piece of the lithium ion battery is a double-sided coating + a metal layer of the middle current collector, and the properties of the coating and the metal foil are different, the response to the laser action is also different. When the laser acts on the negative graphite layer or the positive active material layer, they have high laser absorption rate and low thermal conductivity. Therefore, the coating requires relatively low melting and vaporization laser energy, while the metal current collector is very effective for the laser. It has a reflective effect, and heat conduction is fast, so the melting and vaporization of the metal layer increases the laser energy. Figure 7 shows the copper composition and temperature distribution in the thickness direction of the pole piece of the single-sided coated negative electrode under the action of the laser. When the laser acts on the graphite layer, due to the characteristics of the material, the graphite mainly vaporizes. When the laser penetrates the metal copper foil , The copper foil begins to melt, forming a molten pool.
When the process parameters are inappropriate, problems may occur:
(1) The trimming coating falls off, exposing the metal foil,
(2) There are a lot of chips and foreign bodies around the cutting edge. These will lead to battery performance degradation, safety and quality problems, as shown in the right picture of Figure 8. Therefore, when laser cutting is used, it is necessary to optimize the appropriate process parameters according to the characteristics of the living material and the metal foil, so as to completely cut the pole piece and form a good trimming quality without leaving metal chips and impurities.
Laser energy and cutting movement speed are the two main process parameters, which have a huge impact on cutting quality. The trimming morphology of the single-sided coating anode pole piece under different laser cutting process conditions, and the trimming morphology of the single-sided coating cathode pole piece under different laser cutting process conditions. When the laser power is too low or the moving speed is too fast, the pole piece cannot be completely cut, and when the power is too high or the moving speed is too low, the laser's action area on the material becomes larger and the slit size is larger.
The multi-functional integrated design of Yixinfeng automatic pole piece laser die cutting production line (with dust removal) conforms to the design concept of "high efficiency, high quality, low labor, and convenient operation" in today's equipment manufacturing market.
Since the pole piece of the lithium ion battery is a double-sided coating + a metal layer of the middle current collector, and the properties of the coating and the metal foil are different, the response to the laser action is also different. When the laser acts on the negative graphite layer or the positive active material layer, they have high laser absorption rate and low thermal conductivity. Therefore, the coating requires relatively low melting and vaporization laser energy, while the metal current collector is very effective for the laser. It has a reflective effect, and heat conduction is fast, so the melting and vaporization of the metal layer increases the laser energy. Figure 7 shows the copper composition and temperature distribution in the thickness direction of the pole piece of the single-sided coated negative electrode under the action of the laser. When the laser acts on the graphite layer, due to the characteristics of the material, the graphite mainly vaporizes. When the laser penetrates the metal copper foil , The copper foil begins to melt, forming a molten pool.
When the process parameters are inappropriate, problems may occur:
(1) The trimming coating falls off, exposing the metal foil,
(2) There are a lot of chips and foreign bodies around the cutting edge. These will lead to battery performance degradation, safety and quality problems, as shown in the right picture of Figure 8. Therefore, when laser cutting is used, it is necessary to optimize the appropriate process parameters according to the characteristics of the living material and the metal foil, so as to completely cut the pole piece and form a good trimming quality without leaving metal chips and impurities.
Laser energy and cutting movement speed are the two main process parameters, which have a huge impact on cutting quality. The trimming morphology of the single-sided coating anode pole piece under different laser cutting process conditions, and the trimming morphology of the single-sided coating cathode pole piece under different laser cutting process conditions. When the laser power is too low or the moving speed is too fast, the pole piece cannot be completely cut, and when the power is too high or the moving speed is too low, the laser's action area on the material becomes larger and the slit size is larger.
The multi-functional integrated design of Yixinfeng automatic pole piece laser die cutting production line (with dust removal) conforms to the design concept of "high efficiency, high quality, low labor, and convenient operation" in today's equipment manufacturing market.
