Continuous rolling is a key process in the manufacturing of lithium-ion battery electrodes, following coating and drying. Its core purpose is to compact the loose and porous electrode coating after drying to a predetermined thickness and density through the enormous pressure generated by precision rollers, thereby optimizing the internal structure of the electrode sheet and providing stable high energy density and excellent electrochemical performance for the battery cell.

The standard workflow mainly includes the following steps:

Unwinding and importing: Install the coated and dried mother roll of the polarizer on the unwinding device, and the polarizer is smoothly pulled under constant tension control, and imported into the bite port of a pair of parallel arranged hydraulic pressure rollers (usually high-temperature hard steel rollers).

Hot pressing and compaction: The polarizer is instantly compacted under extremely high linear pressure (usually up to tens or even hundreds of tons) and controllable temperature (usually heating the rollers) when passing through the gap between two opposing rotating rollers (roller gap). This process reduces the gaps between the active material particles, enhances the contact between the particles and the current collector, thereby reducing the porosity of the polarizer and improving its energy density and conductivity.

Rolling and monitoring: The compacted polarizer is exported from the pressure roller, and the online thickness gauge monitors the thickness and consistency of the polarizer in real time, forming a closed-loop control. Finally, the polar pieces that reach the target density are rewound into neat rolls by the winding shaft under constant tension, for use in subsequent slitting processes.

The core value of this process lies in ensuring that the polarizer is compacted to the target thickness and surface density by precisely controlling the four parameters of pressure, roll gap, temperature, and tension. This not only directly determines the energy density of the battery, but also the uniformity and consistency of its compaction are the basis for ensuring low internal resistance, high rate performance, and long cycle life of the battery.