Lithium-ion Full Battery Manufacturing Process Training--Coating

 1.Coating Basics

Purpose: To uniformly coat a fluid slurry onto the surface of a metal foil, dry it, and produce a battery electrode

Principle: The coating roller rotates to carry the slurry, and the amount of slurry transferred is adjusted by adjusting the gap between the doctor blade and the roller. The relative rotation of the back roller and the coating roller is used to transfer the slurry onto the substrate. Subsequently, the solvent in the slurry is evaporated through drying and heating, causing the solid matter to adhere to the substrate.

Lithium-ion Full Battery Manufacturing Process Training--Coating 2

 1.Electrode Shedding

Negative electrodes are prone to powder shedding

Main reason：

1.Formula issues,insufficient bonding strength leading to material loss

2.Excessive baking temperature,rapid solvent evaporation resulting in SBR

bleeding.Insufficient adhesive between the material and the current collector leading to material loss

Lithium-ion Full Battery Manufacturing Process Training--Coating 3

1.Coating Basics

Purpose：To uniformly coat a fluid slurry onto the surface of a metal foil, dry it, and produce a battery electrode

Principle:The coating roller rotates to carry the slurry, and the amount of slurry transferred         is adjusted by adjusting the gap between the blade and the roller. The relative rotation of         the back roller and the coating roller is used to transfer the slurry onto the substrate.         Subsequently, the solvent in the slurry is evaporated through drying and heating, causing         the solid matter to adhere to the substrate.

 

Lithium-ion Full Cell Manufacturing Process

 1.The function of adhesives

Cathode and anode slurries：

Provide viscosity to ensure that particles in the slurry do not easily settle and maintain sslurry stability

Provide viscosity for good fluidity

Provide viscosity to facilitate effective dispersion of materials

Lithium-ion Full Cell Manufacturing Process Training--Soft-Pack Battery Cell Encapsulation

 1.Baking

1.1.The main purpose of baking is to remove moisture from the bare cell

H2O can cause the decomposition of LiPF6, leading to an increase in HF levels:

H2O can react with organic solvents in the electrolyte to produce alcohol and CO2, for example:

During the formation process, H2O can decompose, producing H2, consuming lithium ions,

reducing the initial efficiency and capacity of the battery, and damaging the battery interface.

Lithium-ion Full Cell Manufacturing Process Training--Baking and electrolyte injection

1.Rolling Principle

Roll pressing is a process that utilizes a roll press machine (as shown in Figure 1,the roll press machine used in the industry consists of three core components: a pair of rollers, an unwinding device, and a rewinding device) to compress the thickness of the electrode (as shown in Figure 1). This compression increases the compaction density of the electrode coating, reduces the thickness of the electrode, and ultimately enhances the energy density of the battery.

Lithium-ion Full Battery Manufacturing Process Training--Rolling

1.Process Flow

The main components of a lithium battery include a positive electrode with an active material typically being lithium cobalt oxide, a separator made of PP or PE composite membrane, a negative electrode with carbon as the active material, organic electrolyte, and a battery case made of aluminum-plastic composite film. The manufacturing process involves slurry preparation, film coating, assembly, and formation. In recent years, electronic products have become increasingly thinner and lighter, with faster charging speeds and reduced space, resulting in higher demands for the energy density of lithium batteries. Lithium batteries need to be continuously updated and improved to meet these demands, further trending towards smaller, lighter, and thinner batteries. The related topics of lithium batteries have always been a hot research focus. Adopting suitable materials and cell manufacturing processes can improve battery performance. For specific materials and processes, please consult Canrd!