Slurry mixing is the first key process in the manufacturing of lithium-ion battery electrodes. Its core purpose is to mix raw materials such as active substances, conductive agents, binders, and solvents uniformly in a mixing device according to specific formulas and processes, forming a stable, particle free, and bubble free suspended slurry. The uniformity and consistency of the slurry directly determine the quality of electrode coating, and ultimately affect the performance and safety of the battery.

The standard workflow mainly includes the following stages:

Preparation for feeding and pre dispersion: According to strict formula ratios, liquid solvents (such as NMP for the positive electrode and deionized water for the negative electrode) and binders are usually first added to a vacuum mixer and stirred at a lower speed to fully dissolve the binders and form a gel solution. Subsequently, conductive agents and active substances are added in batches, and preliminary wetting and dispersion are carried out by low-speed stirring to avoid powder agglomeration and dust.

Vacuum high-speed mixing: Close the mixing tank and pump to a higher vacuum degree. Switch to high-speed stirring mode in a vacuum environment. The high-speed rotating blades generate strong shear forces, which can thoroughly break down particle aggregates, allowing various materials to be fully mixed and evenly dispersed, while effectively removing bubbles carried in the slurry.

Dilution adjustment and discharge: After reaching the preset mixing time and viscosity, switch to low-speed mixing mode, and if necessary, add the remaining solvent for viscosity adjustment to achieve precise solid content and flowability requirements of the slurry. After mixing, transfer the homogeneous slurry to a temporary storage tank or directly transport it to the hopper of the coating machine, and continue to stir slowly to prevent settling.

The core value of this process lies in obtaining a slurry with stable viscosity, good flowability, and uniform distribution of various components through precise control of feeding sequence, stirring speed and time, vacuum degree, and temperature. This is the fundamental prerequisite for ensuring uniform and consistent subsequent coating, avoiding material dropping, and thus manufacturing high-performance and high safety batteries.