The pole piece encounters shear failure during slitting, and the flatness of the edge after slitting (no burr, no buckling) is the key to inspecting the performance of the slitting machine.
The slitting pole piece should not have wrinkle or depowdering, and the slitting size accuracy is required to be high. At the same time, the burr on the edge of the pole piece should be small, otherwise dendrites will be formed on the burr to puncture the separator, causing a short circuit inside the battery.